After sending them a concise letter involving words retrospective, extortion, dubious and legality, in relation to a SORN/ tax fine they sent me for a car I hadn't owned for nearly a year and a half, they returned my cheque with a very short "Case closed" note scribbled on one of their receipt slips. Result! :)
However, I got another letter forwarded to me from them the other day. It had been sent to my old address, even though they'd managed to understand my letter the first time round and send the cheque back to me. It was to do with thanking me for saying I don't own the car anymore, blah blah blah. Hardly inspires confidence when I'd already told them (and they'd already seemed to understand) that I don't live there anymore!