Perform according to the contract. If there is no contract, it can be settled through consultation. If negotiation fails, you can complain to the other party's competent unit. For example, the superior competent unit of the intermediary is the Construction Committee, and the competent unit of the merchant is the Industrial and Commercial Bureau or the Consumer Association. Such complaints can't fully achieve the expected effect. However, if some companies or enterprises are afraid of the higher authorities, they may be able to solve your problem by complaining. You can try.