Yes, you can unsubscribe to a store 30 days after you subscribe, directly from your Account page. This is to prevent users from constantly subscribing and unsubscribing to stores and thereby getting access to more data than is included in their plan. You can always upgrade to be able to subscribe to unlimited stores.
If you subscribed to a store in error and want us to unsubscribe before 30 days have gone by, simply
contact us.