This is exactly the same annoyance we're now suffering on the former KLM uk flights.
I'd like to book seats
"That is not possible on this flight sir, it is split class"
After change to F70
"That is not possible on this flight sir, it is single class"
FOR GOD'S SAKE KLM, MAKE UP YOUR DAMN MINDS!
Mind you after my last incident with them we've now decided to jump ship and go to Air Canada instead - I just can't take FD any more