Why confirm my request if it's not going to be honoured?

I've asked FNB to change my debit order dates for my loans to the 1st of every month since my payment date changed. I live abroad so I would've probably gone to one of the branches. They confirmed the change on email, even though I still received more email asking for the new debit order date. Now today is the 31st of August and a debit order took place, now what?What about the date that I asked for and FNB confirmed?should I not be able to send money to SA on the last day of the month,the missed payments will count against me.Setting me up for failure fnb, as you customer,really?