By default, all purchases have auto-renewal enabled. If you'd like to cancel the auto-renewal for your membership, here's how:
Go to your Settings. At the top of the page you’ll see your current membership details including expiry date. Click ‘Manage membership’ to see your refund and renewal options.
If you paid with PayPal, you may have an automatic renewal subscription enabled in your PayPal account. To cancel that subscription, log in to your PayPal account. Click here for more information.