Dishonesty is not the right way to make money guys, NEDBANK get's it right, why can't you

Every month my personal loan is deducted on the 25th of the month, I have no problem with that. The salary comes into my account on the 25th so it covers the loan. How ever, FNB's system starts deducting for the loan at exactly 00:00:00 on the 25th. It try to deduct the money, what seems to be once a second, because the salary comes in at 00:00:03 they bill me an extra R100.00 for there not being enough money in the account. I set the debt order date for the 25th because that's the best option to be charged less interest. I don't understand why FNB insists on trying to deduct the money on the first second on the 25th, and the salary is also paid in and reflects on the 25th, why does FNB's system not reflect the salary first and then start trying to deduct the money. It looks like a very dishonest way to ***** customers over and I would like that money back.