Way back in 2004 RBS technically mis-sold me PPI when I got my credit card.
They described it as something that pays your card if you lose your job, they never mentioned any requirements so when I took thinking it sounded like a good idea it was actually useless.
Turns out you had to be in work for 6 months before it was able to be used (I'd only just started the job a month or so ago and it ended up lasting barely 6 months anyway).
Then many years later I tried to claim on it only to be declined due to being on a fixed term contract as my last job, eventually (and apparently only because the contract had been extended by a month) they paid out.
Have debated a number of times claiming since I spent years paying for something I couldn't use but of course the eventual successful claim makes it a bit more morally dubious and the RBS form requires details from paperwork I don't even remember ever getting, let alone still have.