Myself and my partner were asked to give up our pair of middle cot seats in J before once seated after boarding! My first reaction was to say, as long as you can find us another pair of rear facing seats - the crew then went away and said she would be back. At that point I thought people booking with infants can choose seats at the time off booking so they either booked less than 24 hours out (as I got the seat allocated by calling up around T-28) or they just didn't bother selecting the right seats or they were upgraded - So I was ready to say, actually we are not prepared to move when she came back to say don't worry we have sorted out another seat... This experience has made me weary of these seats now!