This happened to me when I was waitlisted for an earlier lax-sfo flight awhile back. I didn't want to bother the agents, and they were announcing names, just not mine. Since I had an F ticket and should've been close to first in line between that and status for any available seat, I was a bit confused when they closed the flight without saying my name. When asked, I was told they'd called me - when I pointed out where I had spent the past 30 minutes (directly in front of the area where she was making her annoucement), it was oh well we'll put you on the next flight. Part of the issue was that I had an F ticket, and they only had Y seats which I would've gladly occupied had I been asked ... oh well, next flight was an hour later.