It’s most likely that your phone is not connecting to the Boostbox.

• Check you have registered your phone number for use with the Boostbox – if you haven’t you need to give us a call. If you’ve changed your SIM, you need to give us a call, so we can re-register your number.
• Check that you have 3G enabled on your phone – it’s usually in the settings menu. If you have a weak 3G or 4G signal, your phone may continue to try and use this until it recognises the stronger signal from your Boostbox – Deactivate 4G on your phone through your settings.

You could try to force your phone to use the Boostbox straight away by enabling then disabling “Airplane” or “Flight” mode on your phone.