The mobile phone sent a short message, indicating that it was not sent but received three replies.

This service can query short messages, which is generally free or inexpensive.

Maybe the cell phone signal environment was not very good at that time, or maybe the owner was too anxious. Remember to wait a moment when texting again in the future.

Moreover, the SMS sent by the service provider will not charge the owner, so don't worry too much.

If you are not at ease, you can send your mobile phone to the maintenance point for inspection.