Cancelation dispute

Good day. I have problem with my Vodacom account. I tried canceling my contract but only to find out that its not cancelled.I called them before 3months the contract to be ended and cancel it and they told me everything is canceled and now I'm prepaid so that I will be able to buy my own airtime,By the month whereby the contract has to be ended I called again to check wherther the contract was canceled but when I found out it wasn't canceled....now they say I owe them and to the contract that they have put me who agreed with them and wheres the proof that I agreed to that contract....cause me I need those records where they say they canceled my contract then we will fix the Metters other than that I don't owe them....