In fact, they had courts where they presided. The system was legalistic; abuses, of course happened.
A Lord on his fiefdom was a law unto himself over his peasants. They had no right to go to the King for a redress of grievances - and they would be executed for such effrontery - and their wife and children raped and killed themselves for good measure.
A court system of the Aristocracy - by the Aristocracy - FOR the Aristocracy.
The people had no rights. The Court was there to sort out conflicting duties - not to recognize the individual rights of the people - they had none.