Let's try the following steps to get your connection back:
1) Restart your mobile phone
Try turning off and on your mobile phone to re-hook to our network. Or you can try turning on/ off flight mode function on your phone.
2) Flight mode
Make sure your flight mode/ airplane mode is disabled in your phone settings
3) Check for software upgrade
Check that you are your phone's software is of the latest version. You can find this under "software update"
4) Test your SIM card using another phone
We need to isolate if it's a SIM or phone issue, you can try inserting our SIM in another mobile phone to try.
If the SIM works on another phone, this would mean that your current mobile handset is faulty and you may need to contact/ visit the manufacturer for further assistance
5) Check your physical SIM card
Take out your SIM and check if there is any physical damage
Try putting back in and see if it fits to your SIM tray
If there is any physical damage on your SIM or you can't put your SIM back to your SIM tray, please contact our customer support.