HELP FNB ... I AM AT THE END OF MY TETHER!

After scrutinising my Transaction History on my banking account, I noticed that I had been charged an amount of R135.00 for "Item paid no Funds" on 22/08/2022. As I had not made any payments on that date due to no funds available, I queried this charge. I was told by Molelekoa at Premier Banking Suite, that I had been charged for a debit that was made on the 25/08/2022 but only went through my account on the 29/08/2022. How does this happen? 22nd, 25th or 29th. When I make a payment with my card, I expect this to go through immediately, not 4 days later. According to her, the charge was due to no funds available ... well, I am struggling and didn't expect the charge to only go off on the 29th!!! By then I am usually broke, but at the same time, why does the transaction detail show as the 22nd. This is not the first time this has happened and right now R135.00 is a lot of money to me. In addition, when I received the notice from FNB that my account was in a minus, I immediately made a plan and had R1500.00 deposited to cover this. Why am I still being charged this R135-00?? I would like FNB to look into this as a matter of urgency and provide me with a proper response otherwise I am going to go to another bank after almost 35 years of being with FNB. This type of service as