Hi Jim, sorry I've taken a while to respond. I would try and follow the details that I have posted as I was in exactly the same position as you mate. Everntually after the letter to higher up the chain I 'only' had to pay a minimal amount VS the £7500 that I was having to spend at the start! A few letters and searches on google saved me £6000! I still have the letter that I wrote if you need it mate, PM me and I'll whip it over to you.
Again very sorry for such a delayed reply.
Mark
PS I sold the car in July 2014 for £9k so that happy owner should have some good motoring, Now living in Australia where SEAT are no where to be seen!