Contract cancelled and still debit me

After completing the form to cancel our 10GIG BIG contract with TELKOM MOBILE on the 1 November 2015, two and half months later, in late December 2015, they finally cancelled the contract after a long struggle of phone calls to their call centre. During this period, they debited us after 21 working days, breach of contract #1, although on their system, our contract was still active at this time, because they could not simply cancel it because that a staff member did not action the request. Whose fault is that? After finally getting them cancel the contract and after much fighting with Telkom call centre, finally the contract was cancelled, and reflected as cancelled on their system. Even so on January 1, 2016, we were still debited for the contract again, breach of contract #2. I opened a case for a refund in December when we were first charged after 21 working days after cancelling our contract. In January I called again to request a second refund for January 2016 for which they again debited us, under the same case number. Telkom's system only works them not for their customers. if you dont follow up with them you hear nothing back. I am still waiting for a R600 refund.