Ridiculous charges.

I have debit orders that go through on the last day of the month . June , money was transferred later in the day .debit orders went through. Fnb still took R180 on the 1st from my account . When I disputed the charge this morning Am told its for insufficient funds on the morning of the 30th when there was no funds. This is unfair Fnb . This is not even the first time. The month of May I also got charged R150 for a similar scenario. I think am moving to capitec.