If the gym cheats consumers, you can ask the gym manager for compensation. If the gym can meet the compensation requirements, it can be settled through consultation. If the problem cannot be solved, it is suggested to call 123 15 to complain, or complain to the local industrial and commercial bureau. If the local industrial and commercial bureau is not satisfied, it is suggested to bring a lawsuit to the court.

First, the way to sue the gym is as follows:

1, the parties may submit a complaint to the people's court;

2, the parties can also complain to the local departments that accept product quality problems;

3. Prepare a copy of the ID card of the prosecution and the ID card of the other party.

II. Conditions for protection of consumers' rights and interests:

1. The plaintiff is a citizen, legal person and other organization that has a direct interest in this case;

2. There is a clear defendant;

3, there are specific claims and facts and reasons;

4. It belongs to the scope and jurisdiction of the people's court to accept civil litigation.

Legal basis: Civil Code of People's Republic of China (PRC).

Article 120 Where the civil rights and interests are infringed, the infringed has the right to request the infringer to bear the tort liability.

Article 183 Where an infringer damages himself by defending the civil rights and interests of others, he shall bear civil liability and the beneficiary may give him appropriate compensation. If no infringer or infringer escapes or is unable to bear civil liability, and the victim requests compensation, the beneficiary shall give appropriate compensation.

Article 167 Where an infringement endangers the personal and property safety of others, the infringed party has the right to demand the infringer to bear the tort liability of stopping the infringement, removing the obstruction and eliminating the danger.

Article 168 Where two or more persons jointly infringe and cause damage to others, they shall be jointly and severally liable.