MN AUTO FINANCE HORRIBLE RIP OFF HUMBLE Texas

 I purchased a car from mN Auto Finance. Before I went over there, I called and spoke to Mike Bonilla. I told him I did not want to waste his time & I did not want them to waste mine. I explained my situation and said the most I can come up with for a down payment is $1,000.00. Definitely not any more. He said that was fine. I ended up signing documents for a 2007 Cadillac CTS. I asked when I would be able to test drive the car and he stated after the paperwork was done. I ended up signing all the apaper work then he comes and says they will need an additional $500.00 down. I told him I do not have it and I reitterated how I had explained this to him before I came to the dealership. He ended up saying they would work with me to get the additional. I said I can come up with it on July 1st. he said that was fine but because all paperwork has to be finalized before teh end of the month, they would have to keep the paperwork saying the additional $500.00 would be due on June 19th. Well after 2 weeks with the car, on June 23, I got into the car and it did not start. I called MN Auto Finance and they stated the car had been kill switched in effect to me not payng the additional$500.00. I esplained the situation and they said well they were working with a new company that does the kill switches for them and sometimes the cars are kill switched the same day the payment is due, 3 days later, or up to 5 days later. They continued to call me for the additional money and one day the lady became very rude and said Look, THIS IS UNPROFESSIONAL AND UN CALLED FOR THAT YOU CANNOT MAKE YOUR PAYMENT. When I ended up going today, July 6th, to get the items left in my car, there were utems missing and the lady that handles the money tried to get me to sign 2 papers, with different paragraphs. She just told me to sign it was a copy of the same thing; in which was a straight up lie. And when I told her I refused to sign the 2nd paper du to the wording and because I was going to report them she began to snicker and said well i have to tell my manager. She begins to explain to her manager that I do not want to sign and while she is explaining this, she continues to snicker and roll her eyes; as if she is not taking me serious. I have asked for my $1k down payment back however, they refuse. Even though I had the car for  only 2 weeks.