Car Accelerates On Its Own problems of the 2013 Dodge Grand Caravan

Was driving down busy city expressway frontage road at approx 40 mph. Accelerated and passed the slower-moving vehicle ahead of me. . . . Upon clearing the vehicle I was passing, released my foot from accelerator, but vehicle failed to return to prior pass speed and instead continued to accelerate faster. Attempted to brake. . . . Pumped the brake hard when that didn't work but no luck. Held the brake pedal in to the floor as far as it would go to counter the engine audibly reving to gain more speed (hoping to slow the accelerate process as much as possible and maybe hold it at its current rate despite the engine still trying to go faster). I rode out the uncontrolled acceleration issue until coming to a long turn lane where I veered off to get away from other cars. Wth a busy intersection approaching quickly ahead of me and the braking not resolving the issue, I threw the vehicle into park and after a brief time it finally slowed to a stop. This is the only thing that worked. . . I even checked to see if gas pedal was physically stuck somehow on the floor mat (it was not), and lifted up from underneath it with my foot to verify this, during this attempt to regain speed control. . I believe it was this in addition to putting vehicle in "park" that actually stopped the engine acceleration/rev so the vehicle could physically stop. . . Ii is valid to note that I previously took this vehicle into the dealership (around 36000 miles) for evaluation with prior concerns over the engine/transmission not seeming to function right/smoothly. . . . The dealership reported that "they could find nothing wrong with it. " & it was returned to me with no adjustment/repair. This vehicle has several of theory same complaints on the web (acceleration stick/engine/transmission) over a span of several year models & nothing is being done about it or even acknowledging it. . . Huge safety issues here.