Air Brake Disc Pads problems of the 1996 Dodge Avenger

The brakes pads have worn out on three different occasions. The original set of brake pads went out after the first 4000 miles on the car. The pads were replaced and went out again at 17000. Finally the pads went out again at 41000. The first two times the car was taken to the dealership to have the pads replaced. The third time I took the car to a brake specialist and was told that the calipers caused the two sets of brake pads to go out. I was also told that the rear brakes were not working and had hardly any wear. I have also replaced the rear shocks three times. I have replaced the rear shocks twice in the past year.