It's possible that Plat was assigned to the seat and was running late from a bad connection. The GA removed them, upgraded the Silver - but when the Plat showed up at the last minute, he/she undid the change.

This is one of those 'if the shoe was on the other foot' issues - if the Silver in question was the late arriving Plat, I'm sure they would have wanted their original seat restored.

I only hope the GA found the Silver a good seat in the back, even if a non-OP member had to be moved.

To the OP - file a case with WE CARE - you are entitled to downgrade compensation. If they refuse, you can PM Scott, our COInsider with the details.