It is amazingly easy to cancel your subscription, just head to your subscription management page and select "Continue to Cancellation Page" at the bottom. Once you have done that, and gone the whole way through to the confirmation screen, you will be redirected back to your account overview and your subscription status should say something along the lines of "Your Premium subscription will end on 22/02/2013". It is worth noting that your account will not revert to free straight away, it will remain on premium for all of the days which you have already paid for.
for the love of god, how do I cancel the RECURRING PAYMENT? I don't want to cancel the subscription yet. I want to prevent it from making me pay next month without having to cancel that particular day. Please help.