Brakes Failed problems of the 2015 BMW X3

I was about to park in a parking lot, driving slowly and carefully between two parked cars. As I very gently put my foot on the brake to stop, the car jolted intensely and did not stop. I then pressed on the brake pedal harder but the vehicle accelerated to a very fast speed. I drove through some large plants and went over a side walk and made a sharp turn to avoid a large building in front of me. I then drove through the parking lot, maneuvering around parked cars, buildings and other objects while the car was speeding up. My efforts to slow the car down failed even after applying auxiliary brake. Luckily there were no pedestrians or moving cars while this was happening! finally I ended up driving up a hill, hoping that the elevation would stop the car. Instead due to high speed, the vehicle was lifted up about 7 feet in the air, hit a large tree and fell in the ground with much force. I have some injuries as a result and currently receiving medical support, hoping that I will not have permanent health issues, which I very much doubt! my car was severely damaged and was totaled. It is clear and evident that there was some kind of technical malfunction that caused the brake failure and acceleration. I contacted BMW dealership where we had purchased the car and also where I had the car serviced one month earlier! they said I must pay for the car to be delivered to their facility in order for them to examine the cause of brake failure. I refused to pay the high price. It is also important to mention that I have been driving for over forty years and I consider myself a very capable driver. I should also add that on the internet there are at least a dozen similar reported cases of this model. Obviously, BMW has neglected to look into this matter. They should investigate their X3 models before someone dies!.