Policy ****mer

I just received a message from FNB saying I missed my debit order whereas there’s money as I type in my account then I decided to my statement for all my policies with them and to my surprise it indicates that i missed 2 if not 3 payments then I decided to checkout my bank statement to check if there was money on the debit order dates and there was money but now I am failing to understand how premiums got missed because it’s a debit order and it goes off on the 25th of every month!FNB needs to answer to this I am tired of them now!