I didn't send the text message myself when my mobile phone was robbed.

There may be a problem with your mobile phone number customer service, such as Unicom, but this possibility is very small.

Another is that there is a very advanced technology of copying mobile phone cards in the market, that is, using other people's mobile phone numbers to spend other people's money to call friends and send text messages.

This is illegal. I think someone may have copied your mobile phone card. You can see if you have any money or go to the local business hall to pull up all the recent call records and SMS records of your mobile phone.