What happens when the service on Plugzio device expires?

You will be notified to renew your service, nothing is lost.

Plugzio dashboard will notify you well ahead of time if the service is about to expire on any of your Plugzio supported devices.

After the end of the device's service period you have the option to renew at the rate defined by the on-going promotion OR you can discontinue the service at which point Plugzio reverts to an "Always ON" outlet, no loss.