FNB doing as they please

A few months ago I had a similar incident with my Standard Bank account, which ultimately caused me to move my account to FNB, expecting better service. However, on the 15th of December FNB debited my account with R10670 without (a) my consent and (b) without my knowledge. Not even a phone call to advise me that they will take the money. I owe money on my FNB credit card, and paying it back is an obligation I won't deny. However, and without even consulting me or considering the effect it has on my wellbeing, FNB took a third of my bank balance. It is December and I now have no means to pay my debts as a result of this act. I will not recommend FNB's services to any member of the public, especially if they are already in financial difficulty. If an arrangement was made, I would have agreed with it. But not even a phone call.