Worst service ever

Im beyond disappointed at customer service i received from vodacom, i had 2 contracts of which one was ending 20th August, Some time in September i went to their store at Mall at Reds they put me on the line with cancelation department to finalize cancelation of the contact, the consultant told me my contract was canceled and 20th September will be my last payment. Now I just received a statement from vodacom the installment has not been reduced as I've been told it would be reduced. As a client am i to pay until Jesus comes even when I take necessary steps to ensure cancelation takes place. And even if i am to reverse the debit order my credit record is at risk because of someone's incompetency.