Poor Customer service and Account handling

The secure chat is not very efficient. I use a easy pay U account which does not have an overdraft. There was no funds available for any debit orders and Fnb then honored a debit order that went through which should not have been honored it should have been an unpaid. When I enquire with fnb why it was not an unpaid they advised Fnb has a flow limit which will honor some payments. I was then instructed to dispute the debit order to reverse it but I then said why must I pay a additional dispute fee for something I did not asked for on top of the first fee for no funds this where I was just thrown around and nobody cared to resolve the issue.