Once sitting in 3A in a 747, an elderly lady was op-upped to 4E. She made it clear she was unhappy being "dumped" in a middle seat, as she "carefully" had selected 17A for her flight. "It is a window seat", she articulated, both loud and clear.
The CSD was soon there to greet and apologize if she was unhappy with the seat, but as the only non-assigned seat in the F cabin was 5F, there was no window seat available. "But, if you so wish, Madam, I can ask the passenger now sitting in 17A to switch seats with you, so you can have your window seat".
The lady grumbled, but reluctantly agreed to stay. After a couple of G&Ts, quickly bolted down, she slept for the entire flight.