Regarding your question, the Shanghai lawyer answered as follows:
1. Both labor contracts and labor dispatch contracts are subject to the labor law. Although the signing subjects are different and the salary standards are different, they must all abide by the rigid provisions of the labor law on holiday wages and overtime wages. Otherwise, workers have the right to demand differential wages.
2. The Labor Law also stipulates three situations in which a contract is invalid, namely, coercion, violation of true meaning and violation of the law, all of which are invalid. Laborers are not bound by such contracts.
3. How to solve the problem: I suggest that you take the form of class action lawsuit, sue the organization that signed the contract with you to the arbitration commission and get your overtime pay back. This kind of class action lawsuit has a good chance of winning, and it has social influence and is easy to attract attention. You can consult a lawyer for mobile phone evidence and litigation matters. I believe that a serious and responsible lawyer will effectively know that you are defending rights.
I hope I can help you and give you confidence! Please leave a message!