declining debit orders as no funds when there are sufficient funds in the account

I had FNB ***** R200.00 in my bank account in one month, I say ***** because I had made provisions for my debit order but the declined it and have the nerve to say no funds when the statement clearly shows sufficient funds, going to the branch to ask them to assist with using the phone was as horrible, today i woke up to a SMS that says my insurance has lapsed due to non-payment so thanks FNB!