Speed Control Cable problems of the 2015 Mazda CX-5

The car accelerates to high rpm's without touching the gas pedal. As soon as car was started engine roared and could not be contained when in gear. When put in drive the car reached over 50 mph without my foot touching gas pedal. When put in neutral the rpm's were revving excessive near the top of the dial. The only thing to get the engine to stop revving was to turn the car off. I had a hard time getting the car to stop. Problem happened both in the city and on the freeway. The first time it happened it was a hot day (100 degrees outside). Car had been driven for about 2 hours and then sat for about 1. 5 hours and then problem happened. Problem happened about a dozen times before being taken to the dealership. I had not used the cruise control that day and do not regularly use the cruise control. Mazda says it's a battery issue and that I need a new battery. There is no way that is the problem. I've never even had to use jumper cables on the car. I bought the car new and have only had it for two and a half years. I'm the primary driver. Car has 43,000 miles. I'm demanding that Mazda replace the car with a similar age car/similar mileage and they are fighting it. I do not feel safe driving that car. I worry that I will be killed when I can't stop the car or that I will hit a pedestrian or other car and kill someone.