Useless debit order

I have a longstanding debit order with multichoice with a premium package. My debit order is usually R969, including my insurances for 2 exploras with extra view and a dstv walka. Yesterday my debit order went off with an amount of R1358. I called them today and was told i was billed wrongly but they can either leave the excess money as credit or have to wait 14 days for repayment. I am so furious with them cause i want my money back and don't want to wait for my own money that was deducted extra because of their incompetence. I was further told if i don't want to wait i can go to my bank and reverse the money myself. What is the point of a debit order, which is supposed to be a convenient way of paying, when you make mistakes, inconveniencing me, and then i have to run around fixing your mistakes. R969 is already alot for dstv, who still wants to pay R1358. I have been considering for a while now to move over to netflix but has been hesitant, the poor service i have received has made me less hesitant but first i will cancel this inconvenient debit order then remove your decoders and throw them in the bin.