Impenitent

/ɪmˈpenɪtənt/

Modern equivalent

Not repenting of sin; unrepentant

What it means

Adjective describing someone who refuses to feel regret for their sins or turn away from wrongdoing

In the KJV

But after thy hardness and impenitent heart treasurest up unto thyself wrath against the day of wrath and revelation of the righteous judgment of God;

Romans 2:5