The phone calls started in mid-December – just a handful at first, but increasing so rapidly that soon a phone line had to be manned permanently, even on Christmas Day ("in case we had someone whose whole life was falling apart, and it just happened to be Christmas Day").

Teresa Jellis has personally taken "something like 300" calls since the crisis broke, most of them in the last fortnight. Last Monday morning, the specialist plastic surgery nurse switched on her mobile after the weekend to find almost 40 voicemail messages from women concerned about their breast implants, some of them extremely distressed.

Breast augmentation has always been a comparatively small part of the business at Spire Healthcare's private hospital in Harpenden, a smart, low-rise compound situated on the edge of the Hertfordshire town. Of 8,000 patients treated each year, only 100 or so have implants, either cosmetically or for reconstruction following cancer treatment.

The hospital has records of the brand of implants used, and knows that only 37 women at Spire Harpenden were fitted with PIP prostheses, the French-made implants now known to have been filled illegally with an inferior grade of industrial silicone not licensed for human use. And yet the phone calls keep coming, many of them from women who know they were fitted with a different make.

"There's just a huge amount of anxiety for any woman who has had implants," says Julia Salmon, the hospital's director. "There are some very frightened patients out there."

This week the Department of Health took out adverts stressing "the NHS will support women with PIP implants", and stating again that the government will meet the cost of removing any woman's PIP prostheses if she is concerned, while stressing that there is no urgent clinical need to do so. The Welsh government has gone further and offered to pay both for removal and replacement, although its health minister was forced to concede she did not know what that would cost.

But on the many internet forums that have sprung up since December, when the French government advised all women with the substandard implants to have them removed, there are few signs of comfort. "The scan confirmed what I knew," wrote a poster on one Facebook group, "industrial silicone in my left armpit lymph nodes. Radiologist asked me if I was aware of what industrial silicone can do, at which point I broke down … all I can say is get these godforsaken things out your body, whatever you have to do."

Another commented: "I've decided to pay out to get them removed and replaced. Gonna do it in the next 12 weeks, just saving hard, every bit of money is going towards paying for this … I'm just too scared to keep these."

Many complain of a confused and complicated picture, particularly for those who do not yet know what type of implant they were given. Transform, a specialist plastic surgery clinic that cannot say which of its 8,000 surgeries since 2001 used PIP, says it has taken 5,000 calls from concerned women since the start of the year.

The Harley Medical Group, which performed 13,900 augmentations in total in the same period, has had to open an 11-strong call centre to cope with the number of calls coming in.

Though the latter issued an apology to its patients this week, admitting that "we should have listened earlier to your individual situations", both have resisted entreaties to replace routinely their patients' PIPs. The Nuffield Health group, which will replace PIP implants without charge, had 300 calls to just one of its 31 hospitals in the two weeks before Christmas, according to group clinical director Viv Heckford, and has fielded many thousands across the group since, even though its surgeons performed only 180 PIP procedures in total across the country.

Upstairs in the operating suite at Spire Harpenden, surgeon Miles Dickson is still in his green scrubs, having just finished removing one patient's PIP devices and replace them with another brand. Like most of the other big private hospital groups, including Nuffield, BMI Healthcare, and a number of smaller operators such as Highgate hospitals, Spire will meet the cost of replacement on all the PIP surgeries it performed, if the woman is suffering distress and wants them replaced.

"We totally have a duty of care, and we're very comfortable with that," says Salmon. "If we say we are a premium provider, how can we differentiate this from any other procedure?"

Replacement is a simple operation lasting 20-30 minutes if everything goes to plan, says Dickson, who is a consultant plastic surgeon at the East and North Herts NHS Trust, and also does a couple of days' private work at the hospital each week.

Though he never used PIP himself, he notes, peering over half-moon spectacles in a cramped consulting room next to the theatre, he's had "loads of emails" from concerned former patients.

His decision to use another manufacturer was largely based on habit. But he says: "I have taken out a few broken PIP implants, before all of this occurred. And I did look at them and think, hmm, these aren't good. It's fair to say that any implant can break, and given time an awful lot of implants, even the best made, will break. Most reputable implants, when they break, don't cause a problem. These do seem to be causing a problem.

"The two or three PIP implants I have removed, where they have been broken, have been surrounded by a rather thick, pus-like fluid, [which is] always quite alarming for a surgeon … whereas with most implants when they rupture, you just have a bit of loose silicone gel that is contained within the cavity that your body has formed around them. It's basically a question of, that comes out, clean it out, put a new one in."

Breast augmentation surgery has been "trivialised", Dickson believes, and the regulatory framework that certified PIP devices as safe was not rigorous enough. "I believe there is a moral, ethical … and medical need, actually, to remove these implants [even where they have not ruptured]. It is all about controlling risk. And we just don't know at the moment what this not-fit-for-human-consumption silicone is going to do in the long term."

The devices he removes will be "quarantined" and then sent for examination, in an attempt to help fill out some of the gaps in what is known of their risks.

Dickson will see seven or so private PIP patients this week, but is aware, given the inevitable lag to NHS services, that there may be "a little wave of patients that will come rolling through the door" for removals on the NHS.

Public hospitals are already experiencing that wave, according to Sue Barter, consultant radiologist at the Cambridge breast unit at Addenbrooke's hospital. "There has been a significant knock-on effect," she says.

"We are now receiving a noticeable increase in referrals of women with implants, who have no idea what implants they have got in and are now panicking, and for many of them their original private providers are saying, 'We can't help you, go to your GP and say you have a lump, and he will send you up to the breast clinic'."

Though some ruptured implants, she agrees, cause the woman few problems, others can be much more problematic, with silicone – "it produces a snowstorm appearance on the ultrasound" – visible outside the implant capsule and in the glands under the armpit. However, she says, "implant failure is a fact", and many – not just PIP – will rupture or leak after about 10 years. "But this is often not explained to the women when they are put in. And really, there is an ongoing duty of care. These women may well need updating later in life."

The decision to have breast implants, Dickson agrees, is "a lifetime lifestyle commitment. If you are taking a 21-year-old who wants breast enlargement, they are probably committing themselves to three or four other operations throughout their lives directly relating to their breasts." For Joanna Lewis, a teacher in central London, these have been a disquieting few weeks. She had implants around 10 years ago, after a lifetime of feeling painfully self-conscious about her "absolutely flat-chested" frame.

She was reasonably confident her implants couldn't have been PIP, having been told at the time that her implants were a new kind that couldn't leak. "But then I read an article where a woman had had real trouble with globules of silicone migrating to her armpits, and she said when she had it done her surgeon had cut hers and showed her that it didn't leak. I thought, holy shit, perhaps mine aren't all right after all."

She looked through her paperwork, then called her GP, but there was no record of her implant type. So she called the British Association of Aesthetic Plastic Surgeons, who referred her to the hospital where she'd had her surgery, only to learn that it had gone into liquidation. Finally she Googled the surgeon's name, found an email address and sent off her details, to no response.

"Then I thought, if I ring and pretend I want more surgery, maybe they will ring me back. So I did, and they did." The woman on the phone told her they were receiving hundreds of inquiries a day, and to be patient. On Thursday she received a one-line email: "I can confirm that we have assessed your file and you do not have PIP implants."

"I think I have been very lucky," she says. For many thousands of other women the wait for information, and reassurance, goes on.