Stripe, the secure payment service that is used to handle credit card charges, requires the administrator to manually cancel recurring payments. Their API does not support any way for people to cancel their charges.
If you email team@freecodecamp.org, Quincy will handle it as soon as he sees it. If you emailed that account and never heard back, the response probably went to your spam folder. Quincy may have responded to let you know that it was cancelled, or he may have needed additional information from you which he never received.