Rediculous bank charges

I just locked on into my account on the App and realized that FNB is *****ing my money. I've been charged R240, R120 and R100 for one unpaid debit order, which one of you bankers is telling me about how your systems work and she was willing to help me to close my account when I raised my concern, without any attempt to address the problem. This is the attitude that we get we question some of your charges. This is bull****, I'm a customer not an IT expert or even a banker. How your systems works, is the least of my worries. Take what is due to in bank charges, unpaid debit order charges and leave what's not yours. Why are transactions approved at the merchant and later we are charged for those transactions? No one ever explained to us when I open accounts how the system works and I was not part of your IT team who developed the systems but I'm punished for your system flaws. There was more than enough funds in the account when I made the purchase +-R693 and it was deducted from my account immediately and now I'm told there was no money in the account hence I'm charged. When I thought I found a better banking partner after I left ABSA, I just discovered that I found a more abusive partner who ***** me without Vaseline. I ordered a second card for my wife on my cheque account since we will be using a joint FNB account and her salary will be paid I to my account . The card was delivered today (06/05/2019 and you can come and collect it. She was reluctant to switch to FNB, I insisted and I regret it. Ek is gatvol with FNB.