Originally Posted by Proudelitist

I have been in that situation. An FA basically didn't want to deal with a poacher and we were already delayed so she told me to take the poachers seat (10 rows further back, window, not aisle) and give up my exit row aisle. She made it clear she wasn't about to do anything about it. Rather than asking HER to see the purser/lead FA I simply walked back and found her myself. Explained the situation, pointed out that I paid extra for my reserved seat, and told her I would VDB myself and they could sort my unaccompanied luggage and take the late. Note, I used the jargon (VDB, Take the Late, etc) and was not bluffing..I had flexibility and miles enough to get another at no cost. She went and booted the poacher, and quite efficently at that. Took less than 1 minute.

The FA's authority is not the FINAL authority. You have the lead FA, the GA, maybe a station supervisor, and flight crew if you want to kick it up a notch.