Brakes Failed problems of the 2018 Jeep Grand Cherokee

I purchased a 2018 Jeep Grand Cherokee limited in September 2018. With barely 1,400 miles on it, the brakes failed when I was in bumper to bumper traffic for two straight hours on 287 in rockland county, NY. I had my foot on the brake as the road was closed due to a truck fire. Suddenly the brake completely depressed to the floor and the car rolled into a mac truck. I had front end damage in the amount of $1,100, which I paid for myself; and, no one was injured, thank god. Jeep would not even give me permission to rent a car in the interim. I called over 25 times and couldn't get past first line customer service. The engineer came and did a very quick inspection of this car. He claims that he didn't find anything wrong with it; but, I know what happened. The car was towed to and from the service shop as I am petrified to drive it. I paid over $40,000 cash for this vehicle upfront. I got nowhere with Jeep corporate. I even tried to write to the president of Jeep; but, did not receive an answer. The dealership won't assist me either. I have read about similar issues on the internet with the cherokee, the compass and the Grand Cherokee. After a month, Jeep corporate sent me a form letter stating that there is nothing wrong with the vehicle, they can't duplicate the problem; and, I should take it up with my insurance company, which I didn't do as this was not my fault. The form letter has no name, address, phone number, nor email address. As a result, I am stuck with this unsafe vehicle, as I can't afford to trade it in and lose thousand of dollars.