To access your account, click the LOGIN link at the upper-right of the Tara Mandala shop page and enter your credentials. If you've never signed up for an account, use the New Customer signup link located below the login boxes.
In order to cancel your subscription, you will first need to log in to your account. Click the Manage Subscriptions link below your name, then next to each of the products you are subscribed to is a Cancel button.
In the Billing Information tab you'll find the current method of payment along with the current billing address. However, this is not the same as the shipping address. You would edit the address in this section if something has changed for the card holder's place of residence or the email address on file.