Generally speaking, it is unreasonable for a gym to return 30% of its cards, but it is reasonable if the contract stipulates that consumers deduct 30% of the fees when returning their cards. Because the content of the contract is the true expression of the will of both parties, the parties shall perform their obligations according to the content agreed in the contract.

Legal objectivity:

Article 509 of the General Principles of Civil Law of People's Republic of China (PRC), the parties shall fully perform their obligations as agreed. The parties shall abide by the principle of good faith and fulfill the obligations of notification, assistance and confidentiality according to the nature, purpose and trading habits of the contract. During the performance of the contract, the parties shall avoid wasting resources, polluting the environment and destroying the ecology. Article 119th of the Civil Code of People's Republic of China (PRC) is legally binding on the parties concerned.