accounts phone number got changed and it’s not mine.

hello! my friend went on tiktok today and it said she’s logged out she tried to log in with her password and email and it said that her number was changed when they tried to verify if it was her. the email & password is the same but the number got changed and she has a email from when they changed the number she only saw the email now. what can she do?? they won’t let her change the number or login without it. it’s a whole different number from another state. she already sent a report but what if they don’t answer back?