How do I unsubscribe my BigCommerce store from Sandbox Commerce?
Screenshot Step-by-step
In the App Builder, go to 'Settings'
Click 'Unsubscribe' from the 'Billing Information' tab
Delete Sandbox Commerce App from BigCommerce
Click 'Apps' in the lefthand menu
Click 'My Apps' in upper-righthand corner of screen
Click 'Uninstall'