I'm looking at using commerce to offer subscriptions for ad free viewing. I have opened a demo and I can see all the options to move a user into a new group but I can't see how to downgrade them using after their subscription expires.

Is it not possible to say have £1 ad free for 7 days and if they don't renew they are downgraded back to the previous group?

When setting up a subscription look in the store and purchase settings,

Return to previous group when purchase expires or is canceled?