I hate to be the cinical a-hole here, especially cause i am new, but i used to work at a shop and it happens all the time. that is actually what that piece of metal is for. its called the pinch weld. pull out your owners manual or jacking instuctions and it will tell you to put your scissor jack right on it. It will not affect the structural integrity, pose any saftey issues or affect your driving at all. go look under 98% of cars on the road and their pinch weld will be bent in one form or another. Prime and paint the bare metal and move on. they will laugh you out of their shop if you go back pissed off. Sorry to be the bearer off bad news, but that is the reality of the situation.