2005 GMC Yukon Denali Xl

WHILE DRIVING ON THE HIGHWAY WITH MY CRUISE CONTROL SET BETWEEN 50-70MPH, I BEGAN NOTICING MY SPEEDOMETER BEGINNING TO JUMP BETWEEN 0-120MPH CAUSING THE LIMITER TO KICK IN AND ME LOSING THE ABILITY TO CONTROL SPEED. KEEP IN MIND I'M ONLY GOING BETWEEN 50-70MPH. THIS LATER BEGAN OCCURRING WITHOUT THE CRUISE CONTROL ON. SHORTLY AFTER THIS BEGAN HAPPENING ANOTHER PROBLEM STARTED. NOW WHEN THE CRUISE CONTROL WAS SET BETWEEN 50-70MPH, THE ENGINE WOULD AUTOMATICALLY ACCELERATE MAXING OUT THE RPM'S AND SENDING THE VEHICLE TO APPROXIMATELY 80-90MPH BEFORE I HAD TO HIT THE BRAKES OR COMPLETELY CUT OFF THE CRUISE CONTROL. LATER ON WHEN I WOULD SET THE CRUISE CONTROL THE VEHICLE WOULD BEGIN TO JERK VIOLENTLY, REVVING HIGH THEN GOING BACK TO NORMAL BEFORE REVVING HIGH AGAIN AND ME SHUTTING OFF THE CRUISE CONTROL. THERE WAS NEVER A CHECK ENGINE LIGHT THE WHOLE TIME THIS WAS HAPPENING. I IMMEDIATELY TOOK IT IN TO THE DEALER I PURCHASED IT FROM, RANDY MARION GMC IN HUNTERSVILLE, NC, TO BE CHECKED. I WAS TOLD THAT I HAD A BAD MASS AIR FLOW SENSOR. THAT WAS REPLACED BUT THE PROBLEM WAS STILL OCCURRING. I TOOK IT BACK A SECOND TIME AND THEY COULD NOT FIND ANYTHING WRONG SO I BEGAN READING BLOGS TO SEE IF ANYONE ELSE HAS HAD THIS SAME PROBLEM. SOME HAD SIMILAR ISSUES AND SAID THE IGNITION COILS MAY BE BAD. I HAD THOSE CHECKED AND ALL WERE GOOD. THIS VEHICLE HAS NEVER BEEN IN AN ACCIDENT AND I AM THE ONLY OWNER. I'VE CONTACTED GM, GENERAL MOTORS, ABOUT THIS AND WAS TOLD THAT THERE WERE NO RECALL ISSUES BUT HAVE YET TO HAVE MY CALLS RETURNED BY THE PERSON HANDLING THIS CASE. THIS VEHICLE IS NOT SAFE AND NO ONE SEEMS TO BE LISTENING.