Good luck! This happened to me a few years back VIE-IAD on Austrian. I check in and requested a bulked if avai - it was so they happily gave it to me (I was *G). The person next to brought on a "lap child" (4 year old!?) and then demanded my seat. Y was almost full and C was 2/3 empty. I asked if I could move to C in exchange for my seat, they said no and I ended up sitting in the 2nd to last row next to a kid who kicked and hit me (and his mother) and threw food for 9 hours!

Good Luck.