1998 GMC Sierra 1500

I HAVE HAD MULTIPLE INCIDENTS WHERE THE BRAKES HAVE TO BE APPLIED QUICK AND HARD IN TRAFFIC OR ON TURNS WHERE THE ROAD IS SOMEWHAT SLIGHTLY BUMPY OR ROUGH AND THE BRAKES WILL CHATTER AND BUZZ, THE PEDAL GOES TO THE FLOOR AND THE TRUCK WILL NOT STOP. ON THE APRIL 1999 INCIDENT THE CAR IN FRONT OF ME STOPPED IN A TURN LANE TO ENTER A FREEWAY AND I HAD TO HIT THE BRAKES QUICK AND HARD. WELL THEY AGAIN RATTLED AND BUZZED, THE PEDAL WENT TO THE FLOOR AND THE TRUCK DID NOT STOP. I IN TURN BUMPED THE CAR IN FRONT OF ME. THERE WAS LITTLE DAMAGE TO THE CAR. MY TRUCK INSTEAD SUFFERED TO AN OVERINFLATED BODY SHOP BILL TO THE TUNE OF #3,000.00. THE SELLING DEALER DID THE BODY REPAIRS AND CHECKED THE BRAKES. MR. RON BYARS SERVICE MANAGER TOLD ME THE BRAKES, AFTER WE BOTH TEST DROVE THE TRUCK AND DUPLICATED THE NO STOP CONDITION ON HARD BRAKE APPLICATION AT SLOW SPEEDS, THAT THIS IS A NORMAL CONDITION WITH ABS BRAKES ON THESE PICK UPS. MR. BYARS ALSO SAID HIS DEMO WAS WORSE THAN MY TRUCK. HE ALSO STATED THERE WAS A CHECK OUT DONE WHERE HE FOUND NO CODES OR PROBLEMS. I HAD ALSO EXPLAINED TO MR. BYARS THAT ON MOST OCCASIONS WHERE I HAD TO HIT THE BRAKES HARD AND THE PEDAL WENT TO THE FLOOR THE FRONT BRAKES WOULD DRAG. TO RELEASE THEM I HAD TO STOP, BACK UP HITTING THE BRAKES AND THEY WOULD RELEASE. THIS CONDITION HAS DAMAGED MY BRAKE PADS AND ROTORS. HE IS TELLING ME GM CAN DO NOTHING TO FIX MY TRUCK. WHAT NEEDS TO HAPPEN, SOMEONE KILLED OR BADLY INJURED BEFORE GM OPENS THEIR EYES. I NEED HELP.