What do I do when I have problems with service?

There are a few quick checks you can do:
1. The device may be outside of the network coverage for the network service provider; to recover, you will need to re-locate to an area covered by the Network provider.
2. SIM card is invalid, please contact your network supplier, if the SIM card has recently become invalid, you need to contact the Network provider to check why the card is no longer valid and how this can be resolved.