Front Seat Power Adjust problems of the 2000 Toyota Camry

I had a 2000 Toyota Camry. My wife was driving it and she is the only one in the car. 1) she stopped at highway, since all cars in front of her stopped. 2) a 98 Nissan hit her car from behind around 50-60 miles/h. My wife's car hit the car in front of her, and the car in front of her car hit another car. 3)even the front section of my wife's was serious damaged, non of the four airbag deployed. This one is not my complaint here, just provided as a reference information. 4)the driver's seat became flat (been damaged by my wife's body, and she is only around 130 lbs) right after the impact, and no more support for the body, (at this situation, seat belt does not help at all), and she slipped out of the seat, and her head hit somewhere inside the car. She got serious concusion. 5) I only saw Toyota tested front impact, side impact, did not see any rear impact. The driver's seat is supposed to support the body at the time, and it failed to stay, and let the body slip out of it, with seat belt only hook the legs. 6) the strength of the driver seat (power seat) needs to be evaluated, and I want an answer from Toyota. 4).