It's by croydon council (even though I was actually in lambeth)!

I am currently trying to help my dad with an ongoing parking fine that is dated back to 2007. he received a parking fine through the post for £120 for parking in a loading bay. From day one of receving this penalty notice I have replied to them stating that he was never given the opportunity to pay the first fine of £60, ~(i even sent them a cheque for £60 which they returned) I have also asked them to provide details of their parking rules as he was parked in a loading bay, and to our knowledge you are allowed to for 20 minutes. I have just been going back and forth with numerous letters, and even attended court to have the appeal form signed. We have now received another penalty charge notice, and they are now claiming £180 plus £5 court fees - Can you please help with wording a letter to them as I do seem to be getting anywhere other than round in circles and as you can imagine I am at the end of my teather and ready to explode. PLEASE HELP!