Over charching

I have received a call from one of their agents last year around Feb who told me my contract with them was ending and if I wanted to renew it, I said I don't want to renew since I was selling the car(Kia sportage) to my surprise they kept deducting until I called them myself in the middle of the year, then I received a statement that I owe them one month they even refferd it to their debt collectors so I didn't even want to fight cause I said they shouldn't renew I just paid it cause it was a small amount. Now I have received another statement. How are this people operating? Because they are inconveniencing me now I want them to listen to the recording that I said I don't want to renew my contract and they must refund all my money deducted after that even the one I have deposited since they are taking chances with me.