I understand the annoyance and frustration of seat swapping especially when you are separated (probably the worst example being when we have been separated by LH when Mrs OG was invol downgraded), but if you have flown on LAN you would be used to seat swapping and know that seat allocations only a game you play during the booking process and often have no relation to reality. Even BA make it clear that seats can change "for operational reasons" - whatever that means.