Party A maliciously defaulted on the final payment of the project, how to recover the final payment?

If you communicate with the other party, it is fruitless to find a labor bureau. It is really impossible to directly sue, because the other party has already passed the acceptance and signed it. It is obviously unreasonable to refuse the final payment on the quality issue as soon as it is requested. You have every reason to sue him! After the other party loses the case, the prosecution fee on your side will be paid by the other party.

But remember one thing, that is, you must not sue the other party beyond the limitation of action. The statute of limitations is three years. If you ask for arrears during this period, then this time is three years from the last time you asked for money. Don't spend three years quietly suing. The other party may refuse to pay back the money on the grounds that the statute of limitations has expired.