FNB monies disappearing and incorrect information provided to justify

I have come to notice that funds are disappearing from my account overnight. It started off small. With R3 or R8 being taken. Then in March i saw that over R 2000 was just taken from my account. What happens is under "messages" you get a real time notification of how much to spent and what your balance is. This is regardless of whether or not the money has cleared with the merchant. If your available balance is below the amount you are paying, then the transaction is declined in real time. Now FNB agents will tell you that the funds haven't cleared with the merchant however us FNB customers know that this isn't the case. If you go sleep, then you will be able to see your last transaction and your available balance. The next day you go to the shop or debits come off and then your account available balance is less than the previous amount (obviously less however much was debited/spent) but still less than what it should be. I have contacted FNB via my app. I have sent them emails with screenshots, and they even rep**** with a "spreadsheet" with values that confirm what I am saying. Before i could respond less than 24 hours they closed they case after emailing me at night. It is my intention to report this matter to the FSCA, BSA and OBS. My question is this, if FNB has the estimated 11 million clients and at random decide to make R2 disappear from each account then they would have taken R 22 000 000. Now i can confirm that they made R 2000 disappear from my account via debit orders coming off...if they did that with even 10% of their clients then this would total R ***. I will be taking to other social channels in order to investigate. If you have a similar situation, please let me know.