FNB loand department are theives and rude

FNB loand department feel its within their right to debit my account mid month, i have to call them and wait 15min before i get a peraon on the line to reverse this payment, an hour later they debit my account again. I have to call to reverse this debit and wait another 20min before i get to speak to someone. This is disgusting service and its theft. My agreement is for a debit to go off the last day of the month, how dare they assume that they they can just debit my account with out permission, surely this has to be against the law. To add insult to injury the both people i spoke to couldnt be bothered to apologise but tlrather spoke to me quite rudely... Im utterly disgusted by the service i received.