I thought I only had one, but reading through these made me realise I have loads..
Morissons. I was saving the vouchers from the morrisons more scheme and my account was hacked and the vouchers all stolen. About £40 I think. They said it was my fault as I must have used the same password on several accounts, and sent me a link to haveibeenpwned as evidence. They've since stopped the scheme, and it was a widespread problem. Only recently shopped there again, it's been about 4 years. I sold my shares (which since increased in value so I lost out again).
A small cafe near my old flat. Busy, went in and waited....staff deliberately avoiding eye contact and us trying to get their attention. Not even an acknowledgement that we were there. I never went back.
Nationwide. Had a transaction on my account that wasn't mine and they refused to refund for ages. It was £100 and I needed it. Had to go into a branch to show them my boarding pass for a flight I was on at the time of the transaction to prove it wasn't me. They just kept saying 'it's verified by visa so must have been you'. I transferred to another bank, and they blocked the transfer (but didn't tell me) as my middle name was missing on the account. Caused a load of hassle with unpaid direct debits.
Hate Audi TTs because of an ex that drove one. Couldn't give a shit about him any more, but still hate the car 😂
Someone I was friends with at uni...we were both slightly older students (mid-late 20's, so not fresh out of school) and we were friends to start with, but then he took a dislike to me and turned people against me. Said I was quiet and was 'withholding information'...none of it made much sense but I didn't defend myself and I felt very isolated. Years later he messaged on Facebook something like 'sorry for being a prick at uni lol'. I asked him why he was, and asked what had a done to deserve it. He came back and said he didn't know what I was talking about, he'd never done anything, etc etc. So basically he'd just sent a generic message to everyone for attention, hoping we'd all say how great he was. Prick.
I was sick while in the US once (viral, felt hideous for days). Last thing I ate was salsa. I know it's not the salsas fault, but I still hate it.