It's funny to read your story (not haha funny, missing upgrades is no laughing matter) because in 2005 the same thing happened to me, with the same redress.
I was flying America West PHX-LAS and was told First Class was full. After boarding, a uniformed pilot was moved up to an empty F seat. I wrote a letter when I got back to Phoenix and was automatically upgraded on a later PHX-LAX flight. Still annoying for both of us though
