Is it necessary to immediately return the stolen money that its owner did not accept to its donors, or after completing the amount that was deducted from it as a debt?

You are thanked for your work and effort. We remind you of the hadith (definition): "Whoever guides to a good deed will have a reward like the doer of it." Since you are an agent for the owners of the money in disbursing it, it is not permissible for you to disburse it for anything other than what they authorized, except with their permission. Therefore, you must inform them of what transpired. For whoever donates their share to you, there is no blame. And for whoever requests the return of their money, you must return it immediately.