Bought a 1999 plymouth breeze?

I bought a 1999 plymouth breeze from my uncle. The night i bought it, i took it for a drive, and I kept having to floor it, probally because of the commuter having to be re flashed, and so that ruined the rod i guess. So i had to get a new engine for it. My uncle who i bought it from, own's heindls car and truck sales. He said he has a new engine for it, but i would have to find a mechanic. Its been about 1 1/2 month, and the mechanic who would do it for 200 never shows up. So now im wondering, am i able to get my money back from my uncle. Before i bought it, he payed 500 in repair's. I drove it that night, before paying for anything. But then like two weeks later, while the car was broken i payed him the 650 for the car, and heindls the 500 for repairs. But i cant drive the car still because of the engine. So scence the car broke before i bought it, and everything can i get my money back, or scence i already bought it can i not. He should of test drove it and HAS to tell me if something is wrong with it..... Thank you