My money held Hostage

I am really fed-up with Vodacom. i cancelled my contract beginning of August. i was advised that my payment at month-end August would not deduct . Low and behold the payment deducted, and deducted in September. i was then advised the the billing was not adjusted . the billing has since been adjusted and contract cancelled, however i am still awaiting my money deducted for August and September. Each time i enquire about this, i am told that there is a massive backlog with refunds and Vodacom was to have this refunded by 25th November. till now i have not received my refund. i in return have refused to pay my acc for the past 2 months as i would also like to hold something hostage towards Vodacom. I am i am very disappointed and i wish i could cancel all my contracts with Vodacom and move to Telkom. They are quick to harrass us for late payments, yet when coming to getting our own money back, its such a mission.