Business ProfileforMTN. View Nissan of Cleveland

We had purchased a used 2016 kia sorento from mtn view nissan. Within a couple weeks I realized it was having issues. I contacted mtn view nissan and told them the issues it was having and that I was wanting to bring it back. They told me to send them my drivers license and social security card and that they would try to get the deal undone. The following week when I brought the car to them they also requested my marriage certificate. They told me they can't undo the deal. When I got home I checked the mail and had received a letter from the lender saying they weren't able to finance the car for me. I contacted the lender and they confirmed it wasn't funded. I brought the car back the following day and the sales man took both sets of keys and the letter I brought in. A week goes by I get a letter from the lender saying they are offering me a lower payment on the car. I called the lender and they told me I would have to contact the dealer to get the deal undone. I contacted the dealer asking for the deal to be undone and was met with an unprofessional sales manager. He said they do not undo deals I told him I hope he sleeps well at night and he told me I will on a pillow full of your cash then proceeded to hang up on me.