Automatic Transmission Control Module problems of the 2015 Chevrolet Volt

I purchased a new 2015 Volt on July 5, with a charged ev battery. I drove it 41 miles in electric mode, and then the car started using gasoline. Once it did, I experienced an issue with very limited acceleration. The car did not accelerate normally from a standstill. The display went slowly from 0 to 1 mph, then 1mph to 2mph, etc, with about 1 second interval in between. It took about 15 seconds to get to 15mph. It did so twice at two consecutive red lights, until I found a parking lot, parked the car and turned it off . Then I turned it back on and drove it again. It accelerated ok right off the parking lot the first time, but about a half mile later, the acceleration problem was back at the next traffic light for a third time. I stopped driving got the car towed back to the dealer. The 3 instances of acceleration issue all happened within the first 2. 5 miles the car was driven on gasoline. There was no warning on the screen; or any diagnostic code recorded in the vehicle according to onstar. On July 6, my dealer could not reproduce the problem when they drove the car from cold. They wanted me to come in and demonstrate it. I declined, as I no longer felt safe driving the car. I got in touch with a Volt advisor and the gm executive office as this was a safety issue. On July 8, gm recommended replacing the transmission control module. The part was ordered and installed. On July 13, my dealer's service manager took the car for an extended 100 mile test drive on gasoline, and actually experienced the issue multiple times. He mentioned that switching the car to neutral and then back to drive was a successful workaround for the acceleration problem. Based on this, gm recommended replacing the drive unit. I did not think such a major repair should be necessary on a new car and was able to cancel the sales contract and purchase another Volt without this issue.