Q: On highway engine revved, accelerated and pedal stuck

The transmission in my car is not shifting correctly. This was a very frightening occurrence when it happened. It made me feel like the car was in control of me, rather than my being in control of it! I was accelerating on the highway and while I was depressing the accelerator I used the paddle shifters to upshift. Even with my foot off the pedal, the engine revved higher and accelerated. Then the RPMs stuck at approximately 5000 RPM. I pressed the brake pedal, but the car wouldn’t slow down. After managing to get around the traffic ahead of me, I took the next available exit on the highway, which was about a quarter of a mile total. Then I was able to slow down the car and turn it off. When I turned it back on, the engine again revved extremely high and the brake pedal stuck to the floorboard. I called for road service, but after that the car started without trouble. I proceeded to the dealership and after they worked on it, I read the receipt. It was apparent they had not understood what had happened. They drove the car but couldn’t reproduce the problem. I had it re-diagnosed by a 2nd dealership and he found that the transmission fluid is burned. I would appreciate your telling me your assessment of this whole experience. Do you think there is anything else besides the transmission fluid that should be fixed?