Why can't I send text messages on my GSM card?

Hello. If you are a customer in Jiangsu, please first check whether the mobile phone is down, and whether the number of the SMS center in the mobile phone settings is your home address. If there is no problem above, please use another mobile phone to change the card for testing. If it still can't be solved, please bring your valid certificate to the business hall. For your reference. Thank you for using China Mobile Communication.