Pathetic and useless service

Really ****ed off and unhappy with the pathetic service from fnb.i have reversed a debit order which was not authorized for the 15th since my debit day is the 25th however it was declined.where does it say that I authorized the debit order for the 15th whereas I clearly gave authorisation for the 24th.if this matter is not dealt with immediately il ensure this review is all over social media since I had enough of fnb terrible service.one agent tells me il recieve the reversal this evening n the next agent says its declined.do you guys know what you are doing.i want the debit order reversed as promised by the first agent.