I use Unicom card. Why is there often no service? I use it all in the city, and now I can't make a phone call or receive a text message?

If the mobile phone prompts "service restriction", it can be detected in the following ways. 1. Please confirm whether your mobile phone is set to airplane mode; 2. Please confirm whether your mobile phone is in arrears; 3. You can go to a place with a good signal and restart the machine; 4. You can change your card and try it on your mobile phone. If it works normally, it is recommended to go to the business hall for testing. If not, it may be caused by the mobile phone system. You can go to the mobile phone repair point to check your mobile phone.