Transfer of early bond payment not successful???

Fnb again has added to my anxiety. From submitting debit cards that are swallowed twice by the ATM and then making me pay for a replacement card to the latest issue. I transfered my payment to my mortgage early on the 24 December 2024. On the 03 Jan 2025 I received a message notification that the payment was not made. I then checked the Fnb app and found that a direct transfer was unsuccessful. How could direct FNB transfer be unsuccessful? I have now made payment late due to FNB itself. This is not acceptable.