1996 GMC G30

IN HEAVY STOP AND GO TRAFFIC DRIVER LET FOOT OFF BRAKE AND ALLOWED VEHICLE TO ACCELERATE APPROXIMATELY 40 FEET ACCELERATOR WAS NOT PUSHED. VEHICLE CONTINUED TO ACCELERATE AFTER BRAKES WERE APPLIED GOING ANOTHER 30--40 FEET BEFORE HITTING ANOTHER VEHICLE. THIS WAS A 4 VEHICLE CHAIN ACCIDENT INCLUDING THE 96 GMC. PRIOR TO THE ACCIDENTY WE HAD TAKEN THIS VEHICLE TO THE DEALER 3 TIMES WHEN THE DRIVERS COMPLAINED THAT THE BRAKES WERE NOT RESPONDING PROPERLY, THE DEALER DID NOT NOTE THE COMPLAI