I got a slow puncture in a rear tyre on my Corsa and took it to KwikFit. They found a large nail in the middle of the tyre and took the tyre off to repair it. The guy then told me that the tyre could not be repaired because I had been driving it flat which I hadn't. He then quoted me £149 for a replacement tyre. The car has 10,000 miles on the clock so the tyre was almost as good as new with a full tread etc.
I asked him to put the spare wheel on the car and to put the wheel and damaged tyre into the boot. I then drove round to Halfords Auto Centre who examined the tyre and told me that it was a perfectly good tyre and that it would cost £19 to repair.