S2R Warranty Claim

I don't know if anyone else has had this particular problem, but I would welcome advice as to the best way to get it sorted.

I was cleaning the bike about 3 weeks ago and spotted that I'd lost most of the paint off a small front cover, and that there was a big chip in the paint just below the joint on what I think is called the sump casing. The engine casings are both fine btw.

The bike's a year old has done about 3000 miles with almost no winter use.

I went down to Riders where I bought the bike and showed Duncan the service manager. His first response was

"Ducati aren't very helpful with cosmetic warranty claims."

On seeing the Louigimoto sticker, his second was "anyway, you've invalidated the warranty by having work carried out by a non Ducati Workshop".

He did agree to phone Ducati to arrage for an assessor to come and inspect the bike, but as of this afternoon, the official response is that my warranty is no longer valid.

The damage is shown on the attached photo.

Any advice as to the best way to get this sorted?