Is repentance incumbent upon one who remained silent about fraud at work against his will, and is he considered to have betrayed the trust?

We advise the questioner to increase in seeking forgiveness (Istighfar) and performing good deeds, and to resort to Allah the Almighty to free him from any liabilities related to his obligations, as the work conditions mentioned are often not free from infringement on rights. Al-Ghazali mentioned in "Minhaj al-'Abidin" that if it is possible to appease the adversaries, then one should do so. If it is not possible, then one must humble himself before Allah and be truthful to Him, so that Allah may appease the adversaries on his behalf from the treasury of His grace, if He knows the servant's sincerity.