FNB is a ****

Good day, I needed some assistance with a reversal from my bank FNB, of two transactions made on the 25th & 26th of August to Rain, The amounts were R140 each. I called FNB to request for reversals as Rain informed me that only my bank will be able to reverse these amounts because they over-charged me....The consultant I spoke to at FNB told me that for each of these transactions FNB will charge me R325.00 meaning FNB will charge me R650 for a R280.00 request for reversal, Can anyone please explain this to me in a way that will make sense to me. unfortunately, I didn't ask for the reference number for the call because I was shocked at what they consultant was telling me, but I do know that calls are recorded .