FNB - Always finding a way to charge you an exorbitant fee for anything

On the 31/12 a debit order of R480 went off my account for Virgin Active, which resulted in my account going into a negative balance. I then immediately transferred money to my debit card (as I generally transfer my money to my credit card as I get more Ebucks) even before the transaction cleared on FNB side. However, a day later the money returned to my account for the debit order and I got charged a R110 for a missed debit order.

How is this possible? I even got a summary email the morning confirming the debit order was successful but yet it came back and a fee was charged. Is this the type of business you running by charging in search fees to clients who ar a already paying high monthly and service fees every month with almost no perks or benefits from your side.