OK, update. I went to the parking office to renew my resident's permit (at the same time still steaming and all set to chew someone's ear off about the unfairness of the double parking ticket). To be fair, the bloke I dealt with was great and reckons if I appeal both I should get one of them...
So after a couple of weeks' holiday, I walk to my car this morning to take my daughter to nursery.
That's strange, I seem to have got a parking ticket. Surely some mistake, I thought - after all, I have a resident's parking permit. But oh dear, on closer inspection my permit expired at the end...