Forced to pay for a vehicle that I don't have

Had a dispute with the car dealership over a brand new car that I bought in May 2015. The car presented twice with starting problems that left me stranded on 2 ocassions and towed to the dealership. The dealership refused to replace the car though they couldn't find the source of the problem but replaced major electronics in the car. I don't trust that car anymore and am very uncomfortable. Pleaded with the bank to cancel the contract and it was promising that it will be possible to cancel. The dealership refused to give consent and the bank finally said they cannot help me. Now I am forced to continue paying for that car which I have so far refused to collect from the dealership eversince. This problem is financially disabling me because I even hired a car to use for about 3 weeks. I finally bought another small car to use since I was then stranded which makes me loose more money. All I want is to cancel this contract because I cannot pay for a car that I don't trust and whose electronics has been tempered without a diagnosis.