FNB: ********** payments made by and Equally ********** Bank

I am so disappointed at FNB. I choose to be civil and as decent as I possible can given that this is a public platform. But I am so angry. On the 6th of March 2021 money to the amount of R21 137,91 went out of my Savings account. The description on my Statement says POS Purchase from Pivot Payment (Uganda). Then on the 29th March 2021 there was another POS Purchase from the same 'company' of R30 987,99. I was not aware of both these payments. Then on the 30th March I got a message saying that my savings account is in a minus of almost R30000. When the purchase was made on the 29th, I only had about R2500 in my account. But FNB ALLOWED THIS MONEY TO LEAVE MY ACCOUNT, TOGETHER WITH THE OVER R28000 THAT WAS NOT IN MY ACCOUNT. So I'm confused - If I go to Pick n Pay and my groceries are R1000 but I only have R999 in my bank account, and I pay with my card, the bank will definitely decline my purchase. But here, someone **********ly purchased something of over R30000 and I only have R2500 in my account. They allow that R2500 to leave my account and give me a minus R28000. I immediately called FNB. Cancelled my card and contacted the ***** department. I called them every week for an update and by the 3rd time I was told that they will escalate the matter and they will call me within 24 to 48 hours with news. After not hearing from them I contacted them again the following week and got the same story. When I called them on the 29th April, they told me that my case was concluded on the 20th of April and that they will not pay me for the money taken from my account as an OTP was sent and used. And no one explains exactly how this happened. Seeing that I didn't get any OTP. In fact I haven't gotten an OTP for Months. Only Authentication, where you go into your app and approve the transaction. So FNB has a couple of questions that they must answer: How did you manage to pay over R30000 from my account if I only had R2500 in the account? Why did you pay them the R2500 if there wasn't enough money available? I need to see proof that this OTP was sent directly to my phone and not routed to some other IP Address. The issue for me is that I could have put my money under my mattress but instead I trusted you with it. You are suppose to keep my money safe. Hence the monthly fees. But you allow this to happen. My hard earned money. And now you keep on phoning and sending me messages telling me that I must pay the minus over R28000. How crazy is that? Is losing my money to this Pivot Payment company not enough? Now you want me to pay YOU for losing my money? Please note that I WILL NOT PAY THE MINUS. If I don't get joy from FNB wrt my issue I will go to the papers and I will get a lawyer. Because I have lost over R23000 because you couldn't keep my money safe. I have always stood up for FNB telling people who complained that I've never had any problems with them. I will now make it my mission to tell others how little you think of your customers. I am sure if I had millions in my account you would hurry to assist me in getting my money back in order to keep my account with your bank. I AM DONE WITH YOU. GIVE ME BACK MY MONEY.