If no contract is signed, you can only bring a lawsuit to the court within the scope prescribed by law.
Legal basis:
People's Republic of China (PRC) Civil Procedure Law
Article 122 Where a civil dispute brought by a party to a people's court is suitable for mediation, it shall be mediated first, unless the party refuses to mediate.
Article 123 The people's court shall guarantee the right of prosecution enjoyed by the parties according to law. A lawsuit that conforms to Article 119 of this Law must be accepted. Those who meet the conditions for prosecution shall file a case within seven days and notify the parties concerned; If it does not meet the conditions for prosecution, it shall make a ruling within seven days and refuse to accept it; If the plaintiff refuses to accept the ruling, he can appeal.