Well, just to put closure on this subject.
After numerous emails and telephone calls to the dealership, of which all were ignored, they did eventually get in touch. Having sought advice I was informed that all I was responsible for was the cost of any repair work carried out, as per my previous posts I had never not been willing to pay this. I did however question the £475+vat cost of painting a door.
The sum I offered has been accepted by the dealer, somewhat less than £500.
I could have called the credit card company, filed for a disputed payment and in all likelihood paid nothing back, not my way.
There was nothing in T&C re non refund of deposit.
I have over the years bought many cars and bikes through dealerships and had it has always been a trouble free, in many cases bordering on a pleasurable, experience...there were many things that turned this episode into a less than pleasant one.
To all that had offered advice I thank you, whether it was in the positive or the perceived negative!