If you have the above terms, did you communicate with the other party at that time, or didn't communicate, they didn't tell you in time. If you ask for a card refund and they refuse you for this reason, you can sue them in court. If the amount involved is small, you can buy a lesson with money for the time being. If the amount involved is large, I suggest you sue them in court.
Buying classes in the gym means that we spend our own money to buy a coach we like, to keep fit and to get in shape. If our satisfied coach leaves, we have every reason to ask the gym to return our cards and classes. These are all reasonable reasons.
Some gyms will sign the contract and refuse your reasonable reasons on the grounds of the overlord clause in the contract. First of all, you can talk to them about whether you can refund the card. If the gym agrees with your reasonable reasons, then this gym still has a conscience, but there are many gyms, and they will refuse your reasonable reasons for their own benefit.
At this time, you must use the weapon of law to protect yourself, because law is the lowest moral bottom line of human nature. In order to earn benefits from you, don't ask for a refund, sacrifice your own interests to earn their interests. There is no need not to sue them in court in order to avoid their own troubles or reduce complicated things, which involves a lot of money. You must sue them in court and consult a lawyer for legal knowledge before washing.
Now many industries, such as beauty salons, gyms, tutoring institutions. They will patiently explain or treat you when paying money, but when it comes to returning money and cards, they will refuse you for various reasons. Be careful when signing a contract, don't fall into their overlord clause, and don't sign a contract with an indifferent attitude.