If you cancel your 30 day free trial, at the end of the 30 days, your Project will reset to Free.
If you cancel within the 30 days, your project will automatically be downgraded after your free trial runs out, and you will not be charged. However, if you do not cancel, and you enjoy Premium, payment will be processed immediately following the end of your trial. If payment cannot be processed due to an issue with a card, you will have 7 days from the 30th day of the free trial to update your card information to continue using Premium. This information will be provided to you through a supplementary email. If by the end of these 7 days, you have not updated your card, your Project will be automatically downgraded to Free.
For more information on what happens to your Premium Independent Project when it is reset to Free, click here.