Vodacom not wanting to terminate contract

My contract ended in December I was under the impression that I need to cancel my contract 3 months before it ends so I called vodacom they said they will send me a SmS and an email which I'm still waiting for so the mail was supposed to be proof that the contract has ended I went to vodacom they told me the don't cancel contracts at the store I need to call I explained that I have already called so they said no I must call again 30 days before the contract expires I called 30 days they told me about the SmS again I waited closer to the day when my contract would have been due I called coz I hadn't received the SmS so the lady told me that the number is prepaid meaning that contract has been terminated I was happy end of December vodacom debited me I called them I was surprised the lady was so sorry she said she will discontinue the contract immediately n today I am getting a statement vodacom will debit me for Jan I'm in tears kanti what am I supposed to do to get rid of Vodacom