I wish someone can help you with a good advice. I had the same as you, and I sent tenancy agreement, my V5, showing I have the right to park here, with permit or not. Everyone matches, it was no way to come to an agreed as the display was not very well positioned or visible. At the end I remembered paid about £400 to £500 for all the fines, as they were keep coming every single night and by the time I received the first letter I had already about 6 fines.
