Rebuilt 727 no reverse took off pan help

Yeah the guy it a total pos. Never buy from them I knew I should of just saved up more and went with cope. I just took the car for a drive now to the store and everything was fine till I pulled out the driveway and it seemed like when it tried to shift to 2nd gear it locked up the wheels, and my reverse isn't working again so I just drove home doing like 5 miles an hour. Guess I'm going to have to open it up again or just start rebuilding my old one and maybe buy a cope valve body