What an injustice! / That's so unfair!
Expresses moral outrage or indignation at something perceived as unfair or unjust. Can be used for serious situations or everyday minor grievances.
—They gave the prize to the one who did the least work. —What an injustice!
That's so unfair, the worst always happens to him!
—She was fired for no reason. —What an injustice!