What should I do about the loss of my financial dues after the manager denied them, knowing that my work is illegal and I cannot file an official complaint, and should I entrust my matter to God despite my burning feeling and my fear of the manager's persistence?

Your right will not be lost in this world or the Hereafter, so be patient and wise in demanding it. Seek the mediation of honorable scholars and men of wisdom to help you, for you were negligent in not documenting your right with a contract or witnesses, and by violating the country's laws. Do not humble yourself, and be patient and seek reward from Allah, and supplicate to Allah, especially in the depths of the night.