What is the ruling regarding a wife who goes to the hairdresser under the pretext of adorning herself, despite her husband's prohibition?

The wife sinned by disobeying her husband and leaving without his permission. It is not permissible for a woman to leave her husband's house except with his permission, unless she fears harm by staying. What the wife used as an excuse is not a legitimate justification. It is obligatory for her to repent to Allah Almighty by regretting her action and resolving not to repeat it.