Unauthorised debit order

Notified the bank about an unauthorized debit order. They are sending me to different departments. I am not getting any assistance. I have tried to reverse it online but it doesn't have the option to. One Lady at the call center said it is bank charges . if they are bank charges can FNB explain what I am being charged for as my monthly card fees are charged already, 2. Transaction Description Code6081DescriptionPmt HonfeeCategoryFeesSub-CategoryExcess Fee