Adaptive Cruise Control problems of the 2015 GMC Yukon

The problem initially started around August 19th when my daughter was driving the SUV. It started suddenly flashing multiple service problems ex trailer brake service, park assist service and stability track service. It started flashing them over and over every second and the engine would rev up then slow down which continued even after she was able to pull over and get it into park. It was terrifying for her. We had the vehicle towed to GMC. GMC felt the electrical problems were due to the fuse box so they replaced the entire fuse box and changed all the fuses. Last week, my daughter again was driving home on the highway and the vehicle started doing the same warning but also displayed several more warnings and the car was lurching forward and slowing down over and over again despite trying to maintain a safe speed. She was close to home and thankfully made it safely home. I drove the car the next morning a few miles to see what was going on and it started doing the same thing with alerts, servicing cycling through the dashboard and the speed and rpm kept revving up and slowing down, I could not maintain a steady slow speed as it seemed like the car was braking every few seconds so it kept lurching forward out of control. We had the car again towed to the same GMC. This time GMC changed out all the battery cables going to and from the batter itself. My husband picked up the car a few days later after being told the problem had been fixed. Within a couple miles of leaving the dealership (and thankfully before getting on the highway) the car started again with the lurching, revving and continuous flashing of a multitude of service alerts/failures. GMC had the car towed back to the service center where it has remained as they run more diagnostic tests. We are concerned that there is a serious electrical problem that they have been unable to figure out on this vehicle which has put each of us at serious safety risk when trying to drive it.