Double Apple Auto Sales

I recently purchased a car from this car dealer. I am a high school student, and this was my first car buying experience. I signed paperwork for the car and paid for it, and then took it to a mechanic to have it inspected. I realize now I should have done those things in the opposite order. There were multiple problems with the car including with the transmission and the alternator. I took the car back less than an hour after I bought it because I had changed my mind. The man refused to take the car back and refund my money. I realize now that having already signed the paperwork, he is not obligated to do this. However, he agreed to repair the problems, but later changed his mind and refused the repairs, and told me never to come back to the dealership. The very next day, the car would no longer start. I spoke to the mechanic at the dealership, and he said that he would do the repairs anyway (he was very nice), but the guy who sold me the car (is he the owner? I don't know) wouldn't allow it. He told me never to call again, and even threatened to call the police if I ever showed up at the dealership again. Now, I'm out several thousand dollars for a car that won't even start. I can't get to school and I can't get to work. The dealership promised to repair it, then changed their mind. This dealership is shady, dishonest, and absolutely unwilling to work to resolve problems. This is assuredly the worst of the worst. They cannot be trusted, and you should not shop here.