Canceling a subscription is in YOUR control and goes through paypal (an ebay company) so it's easy and safe.
However, some people still have problems with it, and if you're having trouble please follow these directions:
To find and cancel your subscription on paypal, log into your personal paypal account, and select the History option. Select "subscriptions" from the ‘show' pulldown menu. Make sure you adjust the time period so that your account will appear on the ‘within' option. This is what gets most people, as the default is 'in the past day' and your subscription is probably not that new! From here, you should see your Notaddicted subscription. Click on details and you will find the ‘cancel subscription' option. Once you've clicked this you're done! Hooray! Burn in hell, Notaddicted!