FNB *****ULENT BANK CHARGES

I would like to lodge a complaint with FNB, my FNB funeral cover debit order R1148 debits on the 25th of every month. I have been banking with FNB for more than 5 years and get paid on the 20th-22nd every December. Now they did a debit order on the 16th of December there were no funds available, they charged me an extra R200 for no funds. Why did the deduct so early 16th? Whose fault is it if they made a debit order early where my debit order is supposed to be on the 24th of every month. I am so disappointed in FNB and their *****ulent bank charges.