Refund due but telkom not willing to process this back

I just called into Telkom what poor service from the Gauteng call center last month I called in to change my bank details last week I followed up to ensure it is updated and was told that the debit order won't go off then made a manual payment only to see a few days later that they still debit order my account and when calling in I get told that they cannot process the refund and get told that a manager is on a call and no one is available to assist and also have the agent laughing on the call I am waiting on a manager call back which I doubt will happen how ridiculous you are in credit and they unwilling to process the refund this is pathetic