What should the questioner do about an old debt to a cosmetics company, and what is the ruling on repaying this debt after a long period has passed and the specific owner of the right is not remembered? Should she give charity on behalf of the representative and the driver? How can she fulfill the rights of their owners if they are unknown? And does this affect the answering of prayers?

If the company deducted the amount from the agent, then it is a debt owed to you by him. If you despair of reaching him, then give charity on his behalf with his right. If you find him later, he has the choice: either he accepts the charity, and its reward will be his, and your liability will be cleared, or he demands his right, and you pay it to him, and the reward of the charity will be yours. Ibn Taymiyyah said: "If one despairs of finding its owner, then he should give it in charity, and it should be spent on the welfare of the Muslims." You have done well in striving to free yourself from this right, due to the saying of the Prophet, peace and blessings be upon him: "Upon the hand is what it took until it returns it," and his saying: "Whoever has a grievance against someone, concerning his honor or anything else, let him seek to absolve himself from it today before there is no dinar and no dirham."