What should I do if I am harassed by anonymous SMS?

If there is intimidation, if it interferes with your normal life, you can call the police. As for the attitude of the police, it depends on how much this matter affects you. If it is serious, the police can find out her number registrant by intervening in telecommunications and mobile, but she uses a public phone or a card that does not need real name registration.

In addition, if you use China Mobile's mobile phone, you can open the secretary desk and blacklist that person's number, so that she can't call you, but I don't know if the text message will be received, only that you can screen incoming calls. China Telecom may also screen the blacklist, but it will be opened for a fee.

You can change the number if you don't want to make it so complicated.