Unauthorised Debit Orders

I am demanding an explanation as to why I have unauthorized debit orders coming off my account for the past 3 months, all random amounts ranging between R300 and R900. The debit orders are then reversed a few days later however the bank has the audacity to charge me for the reversal! I am still awaiting the reversal of the latest debit order. I want someone to make direct contact with me as I have to sit for hours on the phone waiting for a consultant to become available. If this matter is not resolved this week, I will no longer continue banking with a bank who *****s from their own clients, because I don't see how this is FNB helping me.