For members having trouble with Facebook see this link for assistance https://en-gb.facebook.com/help/ Though you need to be logged into an account to send a message, may also be able to contact via other platforms.
See more information in this article https://www.businessinsider.com/how-to-contact-facebook-problems-with-account-other-issues It is an US phone number listed there so ignore that (little information on phone anyway).
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My Device- S21 Ultra 5G ( SM-998B/DS ) CSC= BTU , 12GB/256GB
One Ui 4.0,Android 12 Official Version.