Battery Dead problems of the 2016 Chevrolet Impala

On Friday, November 18, 2016 at approximately 5:20 a. M. I was parking my car in a center city parking garage. I was approximately 2 car lengths from the parking spot. I was backing my car into the spot. The car was stopped and I removed my safety belt and lowered the window. I put the car in reverse and depressed the accelerator to proceed into the lined parking spot. The car proceeded at a high rate of speed into a concrete wall. There were no obstructions and the accelerator was not fully depressed when this occurred. I immediately took my foot off of the accelerator and hit the brake but the brake did not respond since this all occurred in roughly in seconds and approximately 20 feet in length. Upon impact a smoke filled the cabin area. I hit my head against the headrest and slightly into the steering wheel. Another parking patron saw this all play out and came to my aid. It was a horrific incident. I am thankful and lucky to be alive. It was as if the car acted on it's own. After putting the car in park all of the lights in the car and the flasher were on. Onstar notified me to ask if I was ok. I explained to her what had happened. After two hours no one came to my aid despite being told someone was dispatched. The battery went dead and it was at that time I contacted aaa to have the car towed out of the garage. It is currently in "brendan's collision, ltd, 210 w. Hillcrest avenue, havertown, PA. I contacted gm immediately after the accident and they took a report. The car was purchased in July 2016 and had 3021 miles on it. It was surreal and I was fully aware of what was happening during this whole ordeal.