Vodacom contract

I took a contract with Vodacom two years ago and this year in July it was ending, prior to it ending i called for cancelation because they advised to us to call month prior canceling the contract and i did that, i called more than 3 times cancelling this contact and it was not canceled because they kept on sending the monthly airtime and statement for to pay for something i called months ago to cancel. Every call is being recorded can they please listen to my calls for prove that i did call and bring back the money they debited in august and cancel their September invoice.