Originally Posted by Zarf4
Also forgot to mention... I asked what would have happened it we travelled on the original itinerary and not said anything. Was told that we would have been downgraded at the airport at the return since they would have caught it and have final say. Lovely.
Of course that's what
they say.

If you had made a proper stink at the airport (i.e., calmly but firmly pressed your point, moving up the chain of command as necessary), you may very well have prevailed. Assuming space was still available in C, that is.