My credit card was from sainsburys bank, I phoned them to no avail, sent a recorded letter and heard back 6 weeks later from the Bank of Scotland who underwrite the sainsburys cards. You HAVE to present your case in your initial letter,as to why it was sold to you unfairly, mine was labeled as ‘credit care’ (not PPI)I was told I needed it as I then worked part time (they were fibbing) I send a letter every few weeks reminding them. The high court sent me a letter saying the case had gone to them and was in line to be reviewed. Digging into getting the money back yourself they have to pay interest and you can take it to the ombudsman for review. You don’t lose any money to companies doing it for you but you tend to wait longer.