Should win. If there is a contract, just follow it. As for the security fee you mentioned, it is not reflected in the contract. It is agreed orally by both parties and will not affect the validity of the contract. As long as the contract is valid, go to court, first make clear the complaint, let the court determine that the contract is valid, and then apply to the court for execution. Or directly request the court to require the other party to perform its contractual obligations. Finally, I suggest you consult a professional lawyer. Anyway, when you go to court, you may need a lawyer.