Is it permissible to unilaterally determine one's wage from the fund when the partners refuse to do so, claiming brotherhood and partnership, despite the worker being the one who performs all the work?

The current contract must be canceled if the share of profit or the wage is not specified, because this lack of specification leads to Jahalah (ignorance/uncertainty) and Gharar (deception/excessive risk), which are prohibited by Sharia. A new contract must be drawn up, clearly specifying the wage or the percentage of profit.

As for the past period of work without specifying the wage or share, the Ajr al-Mithl (customary wage) or Qirad al-Mithl (customary profit-sharing in Mudarabah) should be estimated.