Why do I have to continue paying on a car I turned in 3 years ago?

I could not afford the car so I had them pick it up than they called and said I was responsible for paying the difference of what they couldn’t get when they sold it that has been 3 years now and I still owe over a thousand dollars the lady on the phone told me that if I could pay 850 like today the title would be mine well duh the car is gone and I am paying for it