Debit orders going of before it's time charging me absurd fees!

I was charged R200 for two debit orders that didn't go off on my account. R200! These debit orders were supposed to go off on the 25th of the month, December, but they went off before that. On the 24th of the month I transferred my salary into my account to make sure there would be money for my debit orders going off on the 25th like every other month, and to my shock I saw two dishonoured transactions. Would you please elaborate on these absurdly high fees and on the fact that you let these two debit orders go off before there was actually funds in my account, despite the same debit orders going off the 25th of every other month that I can recall!