Accelerator Pedal problems of the 2007 Audi A4

Audi 2. 0t 2007 (2 mos old)- after accelerating to merge onto the interstate, my car continued to accelerate after release of the gas pedal and the rpms continued to increase. When attempting to brake, the car jerked back and forth and required forceful breaking to decrease the speed. I was able to put on my hazard lights and pull off the interstate. I was able to break suddenly, with continued jerking, put the car in park and turned off the ignition. With the car in park, I turned on the ignition, and once again the rpms continued to increase. The car was turned off and I examined the pedals to see if the mat was pushing on the accelerator, which it did not appear to be. While the car was turned off, I pumped the accelerator multiple times, assuming the pedal was stuck and then was able to turn on the ignition without the rpms increasing. No one was injured, but this was a very scary situation because I felt I had little control over the car.