Paying debit orfers when there are no funds and holding me liable when i have no overdraft facility

I am disgusted at Standard Bank!!! Unfortunate circumstances lead me to not be able to cover account payments this month, but they STILL PAID the debit orders which were presented leaving my account overdrawn when i have NO overdraft facility or credit agreement to allow for this. What is even more amusing, is in trying to get the debits returned, they refuse to return their own debit orders (my credit card, bond and loan) but yet have returned the others. I have battled this for 2 weeks now without success and they are throwing fancy words around like "tolerable limit" which i flatly do not accept if there is no credit agreement or agreed overdraft between us. This is reckless and disgusting that they force me further into debt and leave me with an unusable bank account. SO MUCH FOR GOOD BANKING PRACTICE! (sic)