Accelerator Stuck problems of the 2008 Hyundai Elantra

The gas pedal got "stuck" in the down position while driving, resulting in a problem being able to stop the vehicle. I was going approximately 45-50 mph, passing/merging/accelerating in order to get onto an onramp which curved slightly to go into another main highway. When I pressed on the brakes to slow down a bit for the ramp, nothing happened. My car continued to go at the same speed. I continued to brake, and the car would not slow down. I slid my foot over the gas pedal and could tell it was still completely "down" and making the car accelerate at full capacity. I then glanced down to confirm that the pedal was stuck in the downward position. There was nothing under the pedal, the floor mat was not stuck underneath, nor was it anywhere near where the pedal was pressed down. I clicked my hazards on during the process because since it was an onramp, there was nowhere to pull over. As I continuously pressed on the brakes, the car only slowed down approximately 3-5 mph total, because the gas pedal was stuck all the way down, therefore the brakes were trying to work against the full power of the acceleration. Once the passenger realized what was happening, he helped by putting the car in neutral. This helped slow the car, and I then pulled the emergency brake. The car came to a stop in the middle of a main highway onramp. The cars behind me were able to react quick enough to go around and not hit the car. I tried to replicate the problem in order to help diagnose this issue and have more information to tell Hyundai. Once on a straightaway without other cars nearby, I pressed the gas pedal all the way down, and sure enough I was able to recreate the issue and the pedal got stuck again. Upon trying to recreate it a 3rd time, it did not get stuck and seemed to be working properly. But it did get stuck 2 out of the 3 times. It was terrifying to not be able to stop.