Keep deducting money months after contact ended

<p>I cancelled 2 vodacom data contracts a few months ago. I received the invoices for the oustanding balances and paid the amounts. Then a month or 2 later, a debitorder went through my bank account. I was told that I was given wrong information about the settlement amount. This is now about 4 months later, and now i am receiving thretening letters from your collections department saying I still owe R112!!!! What is this now? </p> <p>My account nr I ********** -4</p> <p>PLEASE SORT THIS OUT ONCE AND FOR ALL AND LEAVE ME ALONE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! </p>