What is Islam's ruling on a husband who refuses to divorce his wife and return her to her home, and conditions her divorce upon her waiving her rights and returning the dowry, knowing full well his wife's poverty and inability to pay the amount, and is his action considered an injustice?

If the husband wrongs his wife by withholding maintenance and housing, he has sinned and disobeyed Allah. His action of keeping her in suspense so she would ransom herself by returning the mahr (dowry) is a grave disobedience that existed in the pre-Islamic era (Jahiliyyah) and was abolished by Islam, which commanded treating women with kindness. Therefore, it is permissible for the wife to present her case to the Sharia judge to prove her situation and remove the harm from her. The judge will then rule either that the husband must treat her as a wife and grant her full rights, or divorce her from him without any compensation.