Deleting a Subscription is easy, but before taking action on this is important to know a few things:
If you delete a subscription, all subscribers associated with that subscription will lose their access and will not renew. Customers will have to either sign up on their own on a new plan or you can manually assign them content or to a new Subscription.
You will not be able to filter invoices based on that Subscription in the Sales Tab
Deleting a subscription that is linked to any of your apps is not possible via the UI. You will need to email firstname.lastname@example.org to discuss deleting an in-app subscription.
Here's how you can delete a subscription:
Navigate to the Subscription Tab. Find the subscription and click on Edit.