Unauthorized debit order

Another nedbank fumble!!! Have you noticed that all my complaints in the past few months have been with regards to my banking!! I woke up to see a pending debit of R9850 on my account, with ref PENDING DEBIT. Called *** to enquirer what the debit was for, that agent said he could see what it was and transferred me to the mag tape department. There as well was told they are not able to see and would only be able to tell me tomorrow. Asked if they can reverse it now, and told no tomorrow. I don't understand how so much money can be debited from my account and my bank not know what its for? My distrust for they bank increases! In ombusdsman for banking services bulletin no 12 for debit orders, says \You can instruct your bank to reverse a disputed debit order. If you report a disputed debit order to your bank within 40 days of it appearing on your bank account