Incorrect amount being debited

We have app**** for the Explora promotion for R799 each month, firstly it took 3 months to deliver the decoder and was delivered without the remote, it was collected and brought a new one... <br> Secondly the terms and conditions on the contract states that an amount of R799 should be debit but with a debit order. An amount of over R1550 has been debited every month, twice in a row. Making an arrangement for the balance to be debited the next month Multi Choice just debit the R1550 again. This is very frustrating as a customer and very unacceptable from Multi Choice, I am not able to withdraw the debit order because its a clause in the so called contract, but Multi Choice can deduct any amount they feel like. How is this not breach of contract.<br>