Refunds
Premium memmber upgrades are eligible for a refund within 14 days from the date of purchase. Additionally, refunds may be issued in the event of server faults that affect the usability of the service.

Cancellation
If you are a premium member and wish to cancel, simply login to patreon or paypal and cancel there. Its instant. Paypal >> 'Automatic Payments' or if you signed up under Patreon then its >> 'My Memberships'

Users who signed up on paddle can cancel anytime from the link in their welcome email.