OK. I'll spend some time, and will expand, but don't expect names.
My mother was suffering from arthritis in both knees, at a moderately young age. My father had been paying for private medical insurance, so they decided to go for knee replacements through the insurance to make my mother's life more bearable.
The first knee was done at a private hospital, by a surgeon who split his time between NHS and private work and was, apparently successfully. But after a few weeks, the expected swelling did not go down, and she could not put weight on the leg or walk properly.
They engaged with the private hospital, who did tests and decided that it was not an infection, and they said was not caused by the surgery, but could not find a cause.
They went to the GP who referred them back to the local NHS hospital. Unfortunately, the surgeon who had operated on my mother was a senior consultant there, and made it difficult for them to see another consultant, and refused any treatment because there was nothing wrong in his eyes, which must have been severely blinkered, because the swelling was incontrovertible.
They tried to get a second opinion, and found that there was no point at the local hospital because of the Old Boy network, with junior doctors and consultants not wanting to cross their senior colleague.
Eventually managed to get an out-of-area appointment, but even here the 'Old Boy' network was operating, and no fault or blame was found, and again they could not find a cause.
They went back to the insurance company, who said that they would only take action if they could prove negligence on the part of the surgeon, and that remedial action would not be funded by the insurance company. Went to the GP, who told them that the NHS beancounters would not fund treatment because they judged the problem as being the fault of the private care provider.
While trying to prove something, anything at all, my parents went to a solicitor, who told them that NHS medical records were available under a FOI request, but the same was not true about private hospitals and treatment. Eventually, the solicitor wrote a threatening letter to the private hospital asking for a copy of the notes for the procedure.
Surprisingly, after much to-ing and fro-ing, they got something back! But on trying to read the copy of the notes, they found that the photocopier that was used had the contrast turned right down, making the notes all but unreadable, and even then it was apparent that there were pages missing.
The next step would have been an escalation of the legal action, but it was clear that all my parents would do if they went down that route would be waste a lot of money, and they would probably either lose or run out of money.
And the irony is that they did get to talk to a slightly more sympathetic consultant colleague of the surgeon, who told them strictly off the record that had they had had the initial operation on the NHS, complications like the ones experienced would have had led to a replacement of the prosthetic with another different one with almost no questions asked.
My mother's quality of life was very poor as a result of this right up to the point where she passed. My father never forgave himself for using private medical insurance, and was very bitter about it right up to his death.
So the result of the cautionary tail is check what will happen if it goes wrong, as the private healthcare system is ultimately not working in your interests.