UNPAID ITEMS CHARGES

I want to raise a concern about my bank account's exorbitant and seemingly unnecessary charges. My salary is paid on the 25th of each month but I was charged about R1400 for debit orders not paid on the 24th while these debit orders are normally paid on the 25th of each month. How does this happen? Can someone at FNB please explain? I need to be reimbursed for these unfair deductions.

Thank you