Bad service that affect my credit record

I have been trying to resolve this issue for almost 2 years now with Cell c.

i had a contract with cell c and i closed it after 24 month. they told me to pay more money to close it, which I did. now out of no where cell c says I owe them and I should speak to their Legal department but when I call Legal department no one is helping me. they keep on telling me that they will call me to resolve the issue. but until when after 2 years of trying to fix this? Cell C please just tell me how much I owe you and is for what! this is my number ***