Poor customer service

am so disappointed with FNB customer service, starting with that secure chat, I had like 3 agents helping me but all of them cut the conversation with any solution . I then escalated to the complaints department which is also not helping. My account is overdrawn by a transaction that I did on 25 November 2022. All I am struggling to understand is how come this transaction is taking money from my account on 8 December 2022. Does this mean pending transactions are still to debit my account? I did all my transaction for the month while I had a positive balance but for some odd reason this transaction was pending without holding any funds!. Now I am charged #Item Paid no Funds twice for one transaction.. FNB bankers could not even tell me which transaction is coursing this issue, I had to do that for them.