Payments for courses are processed by the course providers, not Class Central. You need to contact the provider for questions relating to payments or refunds. Look for a Help, FAQ, Support or Contact Us link on your course provider’s page.
Here are links for some of the large course providers:
Some courses run on a subscription basis. Un-enrolling from a course or closing your account may not necessarily stop the subscription payments. It is vital to follow the provider's correct procedure to cancel subscriptions.