DStv can't deal with client accounts

I've purtace a DStv price lock on Black Friday special. The package is R799 monthly. Installation was done on 14 Dec. On 17Dec I received a sms notifieing me I owe R1682.00.Thesame same day I've phoned the call center to sort this error. For I only have 1 decoder. The call center lady assured me that the problem was delt with and that I only need to pay R799. On23 December I received a message from DStv that the debt order of R1682.00 was not successful. AGAIN I phoned to find out the problem for I only owe them R799.00. Still no explanation or resolf was found. I nou bear the cost for the failed debit order and phone cost. I can't believe it is so difficult to sort out an normal account. I never was in arears with my account. Why can't they just adjust the account to the correct debit amount. Why do I need to keep on phoning I would like DStv to rectify my account and pay me back the banking fees for it is not my fault.