I know you love a good airline seating tale, almost as much as a parking thread.
We booked our holiday six months ago and payed all the extras to have seats together, two adults and two children. The cost was 1,200 euros for short haul return flights, but fair enough we have young DCs and we wanted to sit with them in the extra leg room seats.
When we boarded the plane DH had been moved. The steward was very annoyed, but only because we had not been informed of this at check in. He told us there was no discussion and no changes, DH had to sit where he had been reassigned and that was that. A crew member, working that flight, sat in DH's seat.
I looked after the DCs, I am perfectly capable of looking after my DCs, but I don't want to pay for the priviledge of sitting together and then not get it.
Disclaimer: we've had a shitty year, with various problems and a very recent bereavement so I may be too sensitive over this, but I am fed up.