Other Fuel System Fuel Injection System problems of the 2005 Toyota Corolla

2005 Toyota Corolla. For 18 months I have been taking my car to dealer complaining of the idling problem. I can be sitting at the light with my foot on the brake and suddenly the car begins to idle to the point the car vibrates. I have changed gas, had the injection system checked, but the problem continues. There is something wrong either with the gas line or the motor. During the recent snow storm I was sitting at the light with a 1/2 car length between me and the car in front of me. I was on level road and my foot wasn't on the brake. The car began to idle fast and surged forward. I slammed on the brakes and began to slide. I am repeatedly told there is nothing wrong with the car. However, it is either the injection system, the gas line or the motor, which every it is it is dangerous. They also told me nothing was wrong with the brakes at 30,000 but it turned out to be the master brake cylinder.