It is possible you have two active BitGym subscriptions. You may have either one active iOS subscription and one active direct subscription, or you might have two separate direct subscriptions.
If you are getting notifications from Apple about a monthly BitGym subscription, you should cancel that and allow your direct subscription with us to continue. You can see our cancelation guide here.
If you have two direct BitGym subscriptions you should figure out which one you no longer want and visit https://www.bitgym.com/profile to log in with that account and cancel. If this has happened to you we can assist you with a refund. Please open a support request and let us know which account emails have been billed, and which account you want to have refunded.