Is it permissible for a worker to take his incomplete wage by himself from the money of the employer who burdens him and does not give him his full due, and who betrays and steals from those from whom he imports goods? And is it permissible to continue working for him?

If the wage is agreed upon, the worker is entitled to nothing more, even if he encounters hardship. However, if the merchant reduces the agreed-upon wage, it is forbidden and an unlawful consumption of the worker's money, based on the Almighty's saying: "And do not consume your properties among yourselves wrongfully," and the Prophet's (peace be upon him) saying: "Every Muslim's blood, property, and honor are sacred to another Muslim." It is also forbidden for him to withhold the worker's wage, and to commit betrayal or theft. Regarding the worker taking from the merchant's money an amount equal to his due without the merchant's knowledge, this is the issue of "al-Zafar" (taking one's right by force when it is denied). As for working for this merchant, if your work directly assists him in his forbidden acts, then it is not permissible, based on the Almighty's saying: "And cooperate not in sin and aggression." If your work does not assist him, then there is no harm, though it is preferable to distance oneself from such a person.