Cell C does not care....you are on your own!!!!

I closed my account however Cell C still claims that i owe them,,, of which i don't. They debited my account and took the last premium and then closed my account. Now this is impacting on my credit record because i am now listed for a debt that i know nothing off. I have been struggling to obtain a paid up letter from cell C so i can send the letter to the different credit bureaus. This is the worst thing you can do to anyone. I regret the day i took that data contract.