Accelerator Pedal Sensor problems of the 2007 Toyota Tundra

While driving at approx. 55mph the accelerator pedal on my 2007 Toyota Tundra suddenly dropped to the floor below my right foot. My truck accelerated to full throttle. The cruise control was not on. The accelerator was not stuck to the floor mat. The truck accelerated at a rapid pace and nearly ran into the rear of the vehicle in front of me on the roadway. I attempted to stop the vehicle by tapping on the brakes, then the accelerator and turning the cruise control button off even though the cruise was already off. Nothing responded and the truck continued to accelerate to a dangerous speed. The accelerator was "floored" and would not move. I had to maneuver around the vehicle in front of me and several that passed going the opposite direction quickly. The truck was gaining speed at an incredibly rapid pace. I continued to brake the truck in an attempt to stop the vehicle and prevent loosing control. I then attempted to down-shift the transmission. This caused the engine to rev uncontrollably. The same happened when shifted into neutral in an attempt to turn the engine off with the key. The rpm's were revving so high that I feared the engine would blow up. I pulled my truck into a boat parking area on the roadside and slammed on the brakes while putting the truck into neutral and turning the engine key to off. The engine, brakes and transmission were all smoking from the stress and high rpm's. I had experienced a similar uncontrollable acceleration about six months prior (Jan. 2008) to this one but was able to recover quickly by hitting the brakes and presumed that it was something wrong with the cruise control. Toyota replaced the accelerator pedal sensor assy but would not say whether this was the cause of the uncontrollable acceleration. They said that it was possibly caused by the aftermarket floor mats that I purchased at the dealership. Unfortunately, the pedal dropped from under my foot without my intervention. Toyota has not responded to my calls.