Cancelation of Airtime on an expired contract

We have a contract that expired in April, and now there is still money being deducted which is apparently for airtime and its month to month. We have called to cancel that and we are told that we need to pay cancelation fees as the airtime is not month to month ,but contract. We went to the store and consultant told us we can cancel and even called with his phone, we were taken from piller to post until we left. Vodacom is ripping people off.