I would contact the dealer first and see what they are going to do about it, if they do nothing then I will contact a lawyer, carfax, and the BBB. If it wasn't reported to insurance and the person paid out of pocket carfax won't have it listed to my knowledge. Be prepared to not drive it so you can prove it has been wrecked or repaired shitty.
There was someone who went through this on another board I am on and it took a while but the dealer fixed the car for him. If it were me I'd want my money back. Be prepared for a long drawn out process though.