FNB doubling transaction costs and "Money just disappearing from client accounts"

I noticed money missing from my account (Not the first time) so I decided to have a virtual chat with fnb. First I was told I am wrong and my balance is correct. Then I was told that there is an issue at the moment where "Some transactions have doubled, and other funds just disappeared from clients accounts" (I have screenshots of the communication)" Apparently this will be resolved by the 13th. How can a bank just state that money is disappearing from clients bank accounts !! This is not on FNB.