That does sound uncomfortable!
Not to 'diss' the operating CSD, but I would have done all I could to resolve the situation. The problem with moving anyone into a premium cabin for a little while is what I call the 'lets look at what you could have won' scenario. You see 2 seats, and can't understand why you can't sit there, given the circs. Perfectly understandable.
If I had time, I would have moved people around before take off. Sometimes people don't say anything or a problem with a seat doesn't become apparant until we are checking the cabin before take off.
Then we have to be quick and move people around so as not to delay the flight.
So sorry you had a disappointing experience. Write in - quote your seat number as well - and get some form of service recovery.