The man noticed ₦55 million was lost from his account. He investigated and noticed that the money was stolen by bank officials. That pissed him off and wanted to terminate his fixed deposit of ₦500 million. He was told that the money has been withdrawn. He sued FirstBank. They stole his money.
I'm not surprised at all hearing this, bankers steal a lot and the extent they can go to orchestrate those mischiefs can be very alarming. Maybe they thought the man was dead and started withdrawing his money since possibly he doesn't have a next of kin limited to that account.
A banker friend of mine told me that the reason bank managers read newspaper every morning is to know if any of their whale clients without next if kin is dead so they would withdraw the money without trace.
It's always annoying that simple problems that banks can resolve for you immediately, they would turn you like football until you lose hope and stop coming for the issue and then your disputed funds would be theirs, this is why Bitcoin is the best way to invest funds that you don't need immediately since you'll have total control over your funds without having to deal with middlemen excesses.