It is possible for your credit card to be charged even if it has expired due to a function of Gametize's payment gateway, Stripe.
Stripe has this function known as Automatic Card Updates that allows the saved card information to continue working even when a replacement card is issued by the bank (for example, replacing an expired card or one that has been reported lost or stolen). When the customer receives a new card, Stripe will work with the card networks and attempt to update the saved card information automatically. This ensures that services will not be interrupted by expired cards and reduces the need for customers to update card information whenever a card is replaced.
We would recommend to remove the credit card especially if you are not subscribed to any standard plans or do not wish to renew existing subscription plan. If you would like to request assistance on this issue, please contact firstname.lastname@example.org.