I had a paint issue with my 2007 model not as bad as yours, had lost all paint along the top of the windscreen and the rest of the front end was faded ( or lost the gloss almost looked like it had been lightly sandblasted) I took it into Nissan they took pictures and got quotes from local panel shops, I expected them to say bugger off but a month later they came back and said they would do it, so the front and has been respraid (not a top quality job but looks good) had this done early last year, I don't know why they said no to you.