What a useless bank

I am appalled by FNB and the service I have received so far. Money was transferred into my FNB account from a STD bank customer and I have approached FNB to establish the source of funds, this was on the 24 December 2019. FNB said they will provide me with the name of the person who transferred the funds into my account within 48 hrs. Today is the 13 January 2020 and all I keep getting from FNB are excuses. FNB does not seem to have mechanisms in place to trace the source of funds. Right now I am really frustrated as I do not know when this will come back to haunt me, for all we know the money was ****** somewhere.. What kind of a bank is this that cannot tell its client who transferred the money. For crying out loud this was an EFT any competent institution should not have a problem finding out who transferred the funds. It is no wonder that the R99 **** is worse with FNB clients because this bank is just plain useless and ***********. 4 weeks later they cannot ****** tell me where the money came from??