To cancel your Waffle plan, you'll go to your Account page (avatar in bottom left corner) and then "My Account" then the Billing tab.
Organization Accounts will need to follow this article to get to the Organization Account page.
You'll click the "Downgrade" button. You'll be able to use Waffle until your next billing date, then you'll no longer have access unless you purchase again. We’ll also delete your credit card information when you cancel your plan.
Note: if you cancel your Waffle account, your credit card information will be removed.