Legal analysis: the complaint is divided into four paragraphs, the first paragraph indicates the plaintiff's information; The second paragraph indicates the defendant's information; In the third paragraph, it is stated that the lawsuit request is to ask the gym to refund the money and the facts and reasons on which it is based; The fourth paragraph explains the evidence and its source, and the name and residence of the witness.

Legal basis: Article 12 1 of the Civil Procedure Law. The complaint includes (1) the name, sex, age, nationality, occupation, work unit, domicile and contact information of the plaintiff, the name and domicile of the legal person or other organization, and the name, position and contact information of the legal representative or principal responsible person;

(2) Information such as the name, gender, work unit and domicile of the defendant, and information such as the name and domicile of the legal person or other organization;

(3) the request and the facts and reasons on which it is based;

(4) Evidence and its sources, names and residences of witnesses.