Dstv price lock deal gone wrong

I was phoned by a dstv representitive for a explora price lock deal at R789. Then they deliver the decoder and send somebody to install it. They deduct my previous premium of R829 on 1July. One day they decide to switch the decoder off but i paid for the full month. The person who phoned me did not change my premium to 789 when he phoned me the first time and put the price lock deal on the comp. Then for the second time they switch off the decoder. Now when I looked on my bankstatement they somme deducted R922.55. They cleary dont know what they are doing. I have queried on the 31 July when they put the decoder off but for second time no body told me what my premium is. Nobody has phoned me yet to sort out my account.