Describing that as structural frame damage is a bit misleading.
Personally, while you probably have a right to have some compensation, I think you're making a very big deal out of nothing.
So long as they repair it, keep the history report clear of any indication of a repair, and toss you some free service, etc., I think I'd be fine with it.
Going on record as accident history would be a big no no. If the dealer would have spotted that earlier, they'd have fixed it and sold the car as new I'm sure.