2012 Chevrolet Malibu cruise control problems

My wife was driving east down hwy-40 toward salina, ks. She had the cruise control set on 60 MPH. She began to have a epileptic seizure (she was cleared by her doctor to drive prior to this incident) at that point the car began to slowly drift of to the right side of the road. The car drove over a culver, the rear driver side of the car struck at concrete form and sent the car rolling of into a field the car rolled four times.

Vehicle has the check engine light come on and reduced power kicks in with no warning. Vehicle has been driven at speed on highways when this happens and automatically slows to 40 MPH. Vehicle has been taken to the dealership and repairs made the first 2 times, vehicle has been taken back 3 more times for the same issue, no codes showing in the computer. Issue also reported that if at a stop, vehicle has no response when you step on the gas.