On Sunday, September 10, Facebook suddenly blocked access to my account with a "security screen" demanding that I enter a "security code." The problem is that they had texted the code to a mobile account that is no longer in service.
I sent many notices to the "help" link in Facebook. I got an autoresponse saying my notice would be "used to improve Facebook."
I reset my password several times and received email notices about that at my yahoo email account. The notices had a return address for Facebook security and I sent several emails explaining my problem and asking that the email me the security code, or just remove the check screen altogether. No replies.
I know my account still exists because I get emailed notifications at my yahoo mail account. These are the same notifications seen in the dropdown menu on my account's newsfeed.
I have made screenshots of all these screens if you need them.