2014 Fusion Hybrid - unintended acceleration

[Vaud]

I purchased the car in Nov 2018 from Anaheim Mitsubishi. It drove fine for about two months. In late January, three error lights came on. A wrench(powertrain), an Advanctrac warning, and uphill assist disabled. Another light appeared saying to get off the road. I pulled over and turned the car off. After a moment, I turned the key and put it in gear. The car began to accelerate on its own uphill and reached 35mph. I was able to step on the brake and stop the car. The brake did a "double grab" kind of thing. I turned it off and tried again. It wouldn't start and no lights at all came on, only the radio would work. I had it towed to a Ford Dealer in Torrance. They had it a few days and claimed that Anaheim Mitsubishi had put on an aftermarket alarm and that was what was causing the problem. They disconnected it and charged me $330. I took the car and three days later it all happened again. I had it towed back to the Ford Torrance. They initially tried to get me to authorize a slew of more tests at $150 a pop. I told them I had already paid for a diagnosis that was wrong and didn't intend to repay for a second diagnosis from them. So they kept it for four days and said that it was the body control module. They wanted an additional $1000+ to change it. I asked if they guaranteed this would fix it and they said no. I took the car to an independent mechanic who guaranteed he could find the cause. His diagnosis was $150. After a few days, he said that the problem was extensive and would require a lot of time to diagnose and that it was now going to be $250. He has now had it a week and still no diagnosis. He says the car fails over and over but doesn't give codes. He has unplugged all the modules and replugged them all back in thinking something was loose. The problem occurred for him going over speed bumps and for me going up small inclines. Has anyone dealt with this issue? I have not been without a car for almost three weeks. There is a video attached to this of the car accelerating on its own and holding at 35 with no cruise, no foot or floor mat on the pedal.