Unhappy about the customer Service.

I started a contract with this business to get a vehicle, so now with almost 2 years paying my monthly payment a required without any issues as well as no issues from the company, i want to buy out the vehicle from them, i did call them a while ago where they answered and they did send me the balance to settle. so, i notified via email as requested when i want to do the buyout and then they will give me the updated quote with the banking details. I did everything as requested. But now after sending numerous emails and after a lot of phone calls there is no answer or email replies. What must i do now. Is this company still in business? Maybe if i stop paying then maybe someone will start calling me. I was happy with all the assistance of Planet42, but maybe this was just to get a contract through the books.