FNB Funeral Cover

I paid an amount of R1840.00 into the FNB Insurance Brokers account for the Funeral Cover that I have with them that was in arrears for 2 months because they were debiting on the wrong date (before my pay day), however upon calling them to check if they had received my payment, I was told that I should have waited for them to debit twice. Then my banker asked me to fill in a reversal form, which I did and attached the proof of payment. However, today, they come back to tell me that they will not be able to reverse it. Which means that I have lost my money for good somewhere in the FNB system.