After my mobile phone was turned on, all the previous text messages were gone. . . How to get help back?

There is no folder for SMS. If you want your number, you can look it up in the online business hall. If you want information, you can't take it back. There is no need to call the mobile service phone or Unicom service phone, because the mobile company or Unicom company has regulations that the content of the short message belongs to personal privacy and they dare not disclose it.