"Actually, I don't think I got what I paid for."
But you did get what you paid for
"I paid 3 grand, plus a VIPOW for a flat bed first class seat. I confirmed at time of booking it was a 763, confirmed at gate it was a 763, sat in my flad bed seat for 2 hours, and then was taken out of it by an equipment change"
On your ticket did it say that it was a 1st class ticket for travel in an aircraft with a flat bed on a 767-300 or did it just show as being a 1st ticket from A-B ? If the latter, you got exactly what you paid for.
"Maybe I'm being boneheaded here, but I just don't feel I got what I "paid" for."
Did you get to travel 1st class and did you get to your destination. Given that both were yes, then you did get what you paid for.
It's unfortunate that you had an aircraft change but there is no guarantee of a specific type of seat, just the class. If there was, then they would be shelling out loads to transatlantic passengers who expected 1 type of 1st/business class n got the other thanks to the luck of the draw on specific config.
Dave