Unfairly charged excess on account

Unfairly charged excess on account, got penalised 3 items I made when there was money in my account, my account went in negative due to Bank Charges, a few days later, now FNB tells me they took the money for the items I had recently made to cover their own bank charges, then penalised me for being over when these merchants made their banking a few days later! Not fair! Called business banking and the guys didn't give a damn! Closing this account!