FNB takes your money but gives no answers

I had a debit order scheduled for 30/08/21. The debit order went off and the funds were taken from my available balance. I received an email confirming that the merchant received payment and an email saying the funds have been reserved and it showed that the money was taken from my available balance. On the 03/09/21 I received an email again from FNB saying the funds had been taken again, this then put my account in a negative. I contacted the online banker through my app. I kept being transferred to different bankers, one told me the first transaction was a debit order and second a purchase, the other told me it was a delay in payment. No one has given me answers or put the money back in my account. A banker said they can send me a transaction history and then FNB charged me R91 for that history for their mistake of taking funds twice. Now not only is my money not been returned but I’m being charged more to show them that they took my money twice