Monternet didn't send a message. Why should I deduct the fee?

The reason may be that the mobile phone automatically issues a service application.

Because the mobile phone automatically issues a service application, it will be charged. If you use a fake mobile phone, especially some high imitation ones, there may be some charging functions in the mobile phone. For example, playing games that come with your mobile phone may prompt you with some props. If you neglect to continue playing, it may be allowed by default by the mobile phone system, and the fee will be automatically deducted.

If this happens, you can go to the business hall and ask the salesperson to turn off the Monternet function in the mobile phone, but then you don't need all the services related to mobile Internet access (color ring tones, MMS, wireless Internet access) but can only answer the phone and send text messages.