Messrs Okey Nwosu and Dayo Famoroti have lost their application at the Court of Appeal.
Nwosu was the former Managing Director of the defunct FinBank Plc.
The duo had attempted to set aside their conviction by Justice Lateefa Okunnu of the Lagos High Court.
The appellate court sitting at Tafawa Balewa Square, Lagos, upheld the judgment against them.
The court, however, reduced the restitution from N18 billion to N10 billion on grounds that FinBank had recovered about N8 billion.
In January 2021, Justice Okunnu convicted and sentenced Nwosu and Famoroti to three years imprisonment.
The Economic and Financial Crimes Commission (EFCC) prosecuted them alongside Agnes Ebubedike and Danjuma Ocholi.
They faced a 26-count amended charge on stealing and illegal conversion to the tune of N19.2 billion.
The EFCC said the defendants perpetrated the fraud while they were directors of the bank.