What is the ruling on the amounts of money received by a consulting company as a marketing commission or a percentage from international companies that offer proposals to the company's clients, without the original client's knowledge? And what is the alternative way to provide the service for a fee if these amounts are prohibited? And what is the ruling on amounts previously collected that are difficult to return?

The ruling on taking a commission from a company without the client's knowledge depends on the nature of the relationship:

If you are agents for the clients in the contract, it is not permissible to take a commission from the company unless the client gives permission. Whatever was taken without his permission must be returned to him, or given as charity on his behalf if he is unknown. It is permissible to agree with the client on a fee for the agency.

If you are not agents for the client, and your work is limited to introducing the company to the client and facilitating communication between them (brokering), then it is permissible to take a commission from the company without the client's knowledge, or vice versa, because the broker takes his fee from the one for whom he worked. However, it is a condition that the party from whom the commission is taken must be aware of it, otherwise it would be consuming wealth unlawfully.