messing with my credit record

I opened a contract in 2011. I closed this contract as it came to an end, my number *** has been on prepaid for over 2years now. Last month I secured a credit report from TransUnion to check if there are no mischief being done on my name. Only to find that Vodacom Contract appears to say my balance is 145 and my instalment is 145, this account is still active. I immediately called the contracts department, the lady said she would send an update to the TransUnion. I checked again this month and it still is not rectified. This is playing with my future to obtain credit, I really am disgusted by this type of service from this network and will never use it again. And I advise people who had contracts with them to check their credit records! I want my name cleared ASAP!