BYC debit with no debicheck approval how?

I have a BYC debit that has been going off my account and at first I didn't notice because it's small amounts out of the blue and they keep increasing but not so much as to alert me or gove me an alert, FNB doesnt help instead they keep sending me to all these departments, there's something called debicheck so how did this go off when I didnt even get a notification to approve. Fix this FNB