Can anyone advise on this please? At the start of this year, I changed jobs (after a long time with previous company). For several months, I was over paying tax due to being taxed on the benefit of having a company car and private medical - which I no longer had. After 4 phone calls to the tax office over a couple of months (each one about an hour long), they finally confirmed my tax code was now correct (in July) and said I was due a refund of £2,700. I asked them to double check, they ran through it all with me and confirmed it was 100% correct and I was owed the refund, which I then claimed.
Today I received a letter saying I have underpaid tax and I owe £1100, which they will claim back from me from April onwards. This is really frustrating given I spent months trying to sort it, having multiple phone calls with different people, each one saying there had been a mistake by HMRC following my last call. So from April I will be £100 a month worse off, despite doing everything correct and wasting hours on the phone. Is there anyway to appeal their mistake? I'm guessing not but just wanted to check in case anyone has a similar experience! Thanks in advance