Disappointed and Disgusted by FNB and their service

I have been doing cash payments into my credit card and Fnb even after receiving the payments on time still run debits of my account leaving me with a reversal fee of R110. I called in to cancel debit order and Fnb refused to cancel debit order . Even after receiving my payment on time they refuse to reverse the debit order fees that they charged me .This is not fair on the client who is not deviating from paying account. Fnb is robbing their clients , I want the charges reversed for the debit order fees you charge me although receiving my payment cash . I asked for the debit order to be cancelled but you refused and I will not be held liable for that.