Vodacom accounts dept messed up and stole my money

So Vodacom call centre gentleman Tumelo Barres does not know what he is saying because my contract was reinstated on the 24th Oct as the lady who spoke to me on 21 or 22 had said the contract will not be cancelled and gave me reason to not cancel. Now Vodacom says I owe them money of R329. Why is it that I owe them money when an advance payment of R5700 was done and my account was just reinstated on 24 which means my contract runs like normal and there is no new contract signed for. The lady at cancellation Nicolene Peters spoke to me this morning and explained that accounts department has not put a credit on my account so now they are expecting me to make payment but have ****** my money expecting more money to be paid every month when the contract is the same so I will pay Vodacom lots of money and they can continue *****ing a poor man's money