As indicated on the “Join” page when you subscribed, your membership subscription automatically renews at the end of each term, and there is no fee increase for as long as you remain a member. You may cancel or upgrade at any time. Cancellation of your membership is done via PayPal. Sorry, no refunds on previous subscriptions.
To cancel the subscription before it renews again, log in to your PayPal account and go to your 'profile', 'my money' and 'my preapproved payments' cancel the subscription there. Canceling your subscription will immediately stop all future scheduled payments for this subscription. Alternatively, you can find your last payment made in PayPal and click on the transaction details. There will be an option there to cancel.