What is the Sharia ruling on my remaining in my job as an accountant, knowing that there is manipulation in informing the factory owner about daily sales? Do I bear a sin if I do not report that? And what is the ruling on my salary in this case?

If the seller and the manufacturer agree on a cash sale, the agent must adhere to it, and it is forbidden for him to violate his client's instructions, due to the breach of trust, deception, and falsehood that would result. One must refrain from fulfilling the manager's requests if they involve disobedience (to God), even if it leads to unemployment, because sustenance is in the hands of Allah, and what is with Allah can only be attained through obedience to Him.