System automatically upgrades you if on debit order

Every month I get debited triple the amount I have subscribed for. When I call and ask for explanation I'm told I have upgraded by the system. What a joke? Is it that bad with multiple that they just debit any amount they wish from our account? This has to stop. I'm not even watching this I'm on Netflix, this is so I get access to the ZA news and yet they wanna charge me arm and a leg. No! That's uncalled for.