why is it so difficult to cancel a vodacom account after the contract term

I have been trying to cancel my account since the beginning of the year and vodacom consultants have not been helpful. Every time once i pay the amount in arrears i get even the run around until my account is in arrears again and i cannot cancel. I am now told that my account is in pre legal when i get transferred to pre legal i am told the account is not in arrears so i am being transferred to other departs with no help. Why is so difficult to cancel a vodacom account after the contract term