Dstv debit order system fails me yet call centre only wants to believe the system

I have a debit order with you that runs every month like clockwork. I made no changes and the same amount gets deducted. I have not added any service never has a debit order returned. So why suddenly will there be a new higher amount for an arb figure be deducted on my account via debit order. When I phone your call centre they say a lot 9f things about your system, but does not want to accept that there is a problem. Tells me about arrears, then I say but hiw if you run a debit order? Then they change the story to i was deducted less some prev month. How if the same amount has been deducted for ling periods already? There is a problem here and it seems I am at the mercy of multichoice system which seems to have been created by celestial gods and can not be wrong? What is my next step? Will I have to live in fear of the almighty multichoice system and that it may deduct any amount at any time? Or should I rather just break all ties with this system and live in more peace?