FNB Taking money from my business

I have a gold business Account with FNB and I have outrageously high bank fees every month and now today Suddenly I have -R3000 from my account which says Debit card authentication which is UNACCEPTABLE I have calculated every single purchase and got all the emails and slips from every purchase and this does not make sense at all this is not right that -R3000 is not correct and needs to be fixed!