I just had my fuel pump changed out due to a.

I just had my fuel pump changed out due to a recall and my car was leaking gas. After I had it changed out, I had no problems for a week or two. But now everytime I am going up an elevated surfaces, like stopped at a light for a minutue or so and it's surface is slightly up hill, the car basically stalls. The engine is still running, but I don't know if everything was connected right or if it's something else. I don't want to go back to the same garage because they were rude and took me for all my money to change out the fuel pump.