********** debits

I finished paying my 24 month contract in November. The following month vodacom kept deducting the instalments I called them to cancell and change my number to prepaid for two months they didn't debit until today where they debitted more than twice of the instalment I was paying.I called they customer care at 7:10 am spoke to sibonelo who couldn't assist or give me an explanation she said she was transferring me to account kept on hold for 18 minutes while listening to they free music then call disconnected. I want my funds refunded back to my account.I feel it's ***** for them to debit whenever they want to its unconvincing.I just need my funds then I will change another service provider.