R99 unknown debit orders

Im disgusted by standard bank ,theyve been R99,00 unknown debit orders going off my account month ,i dont know the company thats debiting my account ,so now i didnt have funds in my account as a result i was billed with 3 unpaid debit order (R146.00)last month July same happened and they told me they are aware of those debit orders as a bank they trying so much to assist and for now they will help me by reversing the fee,then good they did i was happy ,now this month same thing happened but this time 3 debit orders went off,now i called them to log a query as they said they are aware of the unknown debit orders,was given a number from the merchant that debiting my account their number is engaged and the other number they hung up on my ear, what im angry about is that they aware of those unknown debit order (R99)but they not doing anything about them so now i must be penalized because i didnt have money into my to cater for those ‘unknown debit order’,so they saying they are the third party in this so i might gave those guys my details but they know very well that is a **** ,and they making money with our unpaid fees,and Portia from complaints department was not patient with me because i needed answers ...