overcharging on bank charges

i had unpaid debit orders on my account , absa then charged me 734 rands, which i dont know for what as my monthly charges dont come to that, then again yesterday absa helps themselves to my money stating bank charges, charges for what now because i was charged for unpaid debit orders, over charged, yet i still had to pay those debits, then you charge again for what? so im being charged twice, for what exactly so that means in the month of between end of Feb and beginning of March you've charged me over grand, for what ? cause you didnt even pay my debit orders? i need a clear breakdown not a call from your clueless agents because ive queried this before and they had no answers for me. break it down rand by rand.