2003 Chevy Cavalier My Car still won't work!!

Hi, I have a 2003 Chevy Cavalier LS. I'm so frustrate because I just bought a new battery, fuel pump ( a couple months ago), A new starter and a new key ignition all put in this week. The mechanics claimed to have reprogrammed my car. But, it still is not working. In fact it seem to be doing exactly what it was doing when I first put it in the shop. True, they have gotten it to start but, in 2 days it is back to not starting. I need suggestions on what I need to do. Because I this is costing me big time and the car is still not fixed!!