Telkom unauthorised debits

This month I have been charged an extra R492.00 for event billing usage on my Telkom Mobile Bill. I have never subscribed to any content and am extremely careful a to what I accept or click on when using my mobile. All Telkom can do is cancel the subscription but I still have to pay the bill for some content or game that I have never used or am even aware of. Vodacom at least let you unsubscribe from these billing items permanently. How do the likes of Telkom allow unauthorised debits off your phone when even banks would ensure you are refunded.