Charged for unauthorized Debit orders

Unauthorized debit orders are having a party in my account. On a month to month basis i have to contact standard bank and request for reversal of debit orders that i know nothing about. i phoned about a week ago to reverse two unauthorized debit orders and requested the agent that they block them. I see the same debit order went off again today 6 August for R99 with ref: VAR VH VAR ********** 191 and because i did not have funds in my account you have charged me R146.27 for unpaid debit order. I will not pay for this. it is already costing me time and money to constantly be on the phone with your agents reversing this monies or driving to your branches. Please reverse the charge, I am now tired of this!!!!!