I hate to hear stories like yours. You rely on your dealer to service your bike/car/whatever with care and they screw it up. And what's with this undersized tire crap? A 17 inch tire is a 17 inch tire, and if the dealer sold you the tire he is even more responsible than if you brought the tire in, in which case he should still be responsible for detecting a problem that might damage the wheel. Don't call them scratches, call them scouring, as in enough damage to cause a wheel imbalance.
You have alluded to trying to keep your cool or performing proctological podiatry on the dealer. I presume you don't want to take your bike there in the future for servicing. I know I wouldn't. But don't get carried away if things don't work out. We live in a time of litigation and criminal complaints. You can't smack a**holes anymore. Will cost you thousands of dollars and possible jail time if you do.