FNB Deducting money unnecessarily

I pay my monthly installments on my credit card each month before needed. Today i went on my bank account only to see fnb has deducted money from my bank account for my credit card. I Don't understand why this was done seeing that my payments are always made on time and my auto payments are off.

I want this money to be cleared in my credit card immediately or paid back into my debit card.

I'm getting tired of FNB just doing as they please seeing that this is the second time this happens.