What is the ruling on an employer who deprives a worker of overtime pay, and is it considered unjust to treat a working person and a non-working person equally?

If a worker performs overtime and the supervisor does not pay him his wage, this is unlawful, unjust, and a denial of people's rights. It is a grave sin, especially against the weak. The Prophet, peace and blessings be upon him, said: "There are three whose opponent I shall be on the Day of Resurrection: a man who gave a promise in My Name and then broke it; a man who sold a free person and consumed his price; and a man who hired a laborer, benefited fully from him, but did not give him his wage." Allah has commanded justice and good deeds. Part of justice is rewarding the good-doer and punishing the wrong-doer. It is incumbent upon those in authority over people to act with justice, kindness, and mercy towards their weak.