2007 Mini dealer warranty issue

[Bond 003.5]

2007 "S" timing chain jumped and basically disintegrated the top end of my motor. NW Mini rebuilt the head under warranty with a smile, then told me a magic rock had somehow "worn" a hole in an impossible spot on my "PREVIOUSLY WORKING" AC then refused warranty fix & wants $800 to repair. No luck w/the dealer service or Mini cust service 1-800 line. Anyone have any ideas who I could elevate this to?

[jakesulivan]

They are cheating you. Get it checked by some professional.