Don't complain about the attitude, it takes away from the fact that you're really complaining about the ticket.
Write the letter as above, leaving out the attitude bits, then wait. If you hear from them before the 28 days, then great. If you don't, then pay the fine and then write another letter complaining about the lack of communication. If you still don't hear anything then you can write a further letter saying that they appear to be as rude as the coppers that stopped you