unauthorized payments

i really do not know where Nedbank got the right or authority to pay my debit orders. what if you guys have paid incorrect or unauthorized debit orders...i got a call confirming that im owing the bank 600. they've actually added R90 for each debit order they've paid for me. who said you guys should pay my debts?????? reverse those debit orders i will pay them myself. and reverse the money you took from my account today back to my account please yeeerr