1996 Sunfire (2.2L) Cylinder Head / Timing Chain

Recently I had my car started in my driveway for about 10-15 minutes to warm up. I got into my car and reversed out of my driveway. When I went to put the car in drive and it shut off and would not start anymore. It would turn over but not start. When I sent it to the mechanic to find out why it was not starting I was told that there was not compression in the system and that the head gasket needed to be replaced and the head itself would have to be repaired. I specifically asked if this was the reason for the no start and was told that it was. After "fixing" the "problem" the mechanic failed to get the car to start only to find out that the timing chain was busted. Since then there have been a series of so-called "repairs" required (fixing the head, cylinders and valves 2-3 times) due to mechanical incompotence and error. My Question is - If the car was running fine prior to the timing chain breaking, should replacing the chain make the car start again? To what extent would the damage to the head, cylinders and valves have to be in order for the car not to start? I feel like I am getting screwed around and have been told so by other mechanics that I am. Can anyone help me on this? If possible be as detailed as you can in your reply.