When you subscribe to something you set up a repeat payment against the payment method you used - if you don't want to renew you need to make sure it is set not to renew in your account. I don't have the standard PC set-up so I can't post screenshots, but I think it should be fairly clear if you go to the Platinum Club area of your account (where, if you are renewing, you can adjust the frequency to annual if you want). Note that people paying with PayPal also need to cancel at the PayPal end or the money will be sent regardless of the options at the DAZ end.