You can cancel your Pro plan and downgrade back to the free Paper.li service at any time during the 30 days billing cycle. Once you cancel your Pro plan, your paper will be downgraded to the free service at the end of the billing cycle and you will not be billed again.
To cancel the Pro plan follow these easy steps:
Click on your avatar in the upper right hand corner and go to Account Settings
Go to "Your Papers" on the left hand side of your screen
Choose the paper you would like to cancel
Click "Cancel" and confirm
Pro features will remain active on your paper until the end of the current billing cycle, and your credit card will no longer be charged for this Pro subscription. You can re-upgrade your paper then again at any time.