Lenovo A820T mobile version, SMS is completely unavailable.

Hello, thank you for choosing Lenovo products. Receiving a text message should not be a mobile problem. I suggest that you can back up those important short messages to the cloud or computer (many third-party mobile assistants now have the short message backup function), then clear the short message content and try to send a few short messages, or directly restore the factory settings, but be sure to back up the data. Thank you for your support to Lenovo and wish you a happy life!