The squeeky wheel gets the grease. Make a fuss. File a written complaint with the BBB. Call channel 5. Eventually they will find someone who actually know how to to it. (Sounds like they botched the reframing.)
Most hardware stores will carry these screws. There usually #10 x 3" and the're called "set screws" for door hinges. In most cases with your description of the problem, these were never put in. Just keep in mind that when you put these in, that you "pre-drill for the screw. Otherwise you risk stripping the screw head. In fact, I would go with a 4'-4-1/2" screw, and drill at low speed.There are supposed to be LONG screws(2 1/2-3") in the top(2) and middle(1-2) hinge that reach into the house framing. I am guessing that these were never installed.