Is it legal for the membership card not to refund money?
It is illegal for a membership card not to be returned. In this case, the customer's membership card means that he has signed a contract with the merchant. If the contract can't be fulfilled and the balance can't be returned due to the reasons of the merchants, the customers can protect their legitimate rights and interests by suing.
According to the relevant laws and regulations, a membership card is a contract, and the parties have the right to demand its termination and return the balance owed to the members.