Yes. You need to extend your rental even if you did not use the internet.
Why an extension is required
WiFiBOX is a rental service.
Rental fees are based on how long you keep the device, regardless of whether you actually used the internet or the Wi-Fi function.
When you need to extend your rental
If you will keep your WiFiBOX beyond the scheduled return date, you must complete a rental extension, even if you did not use the device at all.
Rental extensions are required regardless of your circumstances or whether the device was used.