Do I have a chance in not paying for this?

You Hi. So I had a car joint ownership with a man I was with. I had the car about 11 months and I made every single payment automatically out of my bank account. We broke up and he took the car from me. Gave it to his new girlfriend and never made one payment. It got repossessed and now I got a letter saying the money is in collections and if I don't pay it they will garnish my wages. Do I have a chance in winning not paying for this in a court room? I have statements showing I paid every payment on time for 11 months and then they just stop because he takes the car from me. Both our names are on the loan so that's what worries me.