Quebedeaux Buick GMC

I bought a truck from them, signed a contract, and had the truck for two weeks. Dealer calls me up, they made a mistake. I own them 1,500 dollars more. Go down to find out what's going on. They say because it their mistake I only own 750. I tell them I donot want to pay the money, deal off give me back my tade in. They said can give back car it is to late in the deal. Plan on going to BBB and Gm. Stay away from is place.