Three debit ordes after arrangement was agreed on.

Made an arrangement for debit order with Nedbank for additional debit so that whatever amount am behind with can be collected.To my surprised Nedbank took R14500 from my current account . My life is stuck because of their, there were supposed to take only R1112. My credit record will now be tarnished because there won't be enough cash to cater for another debit orders .It takes a day for payment from one bank to another...Even if they reverse my current account will tarnish. This is unacceptable.