If the miles were deducted and you have a proof that those miles were deducted for the flights you reserved, they have no right to cancell the booking. The booking in F is very tricky because they do not have a lot of seat available for award in that class. Quite often, airlines have call centers. Agents do not know the rules or book with the wrong code -A,F, P ???. The agent might have found a seat in First class but then...oops it was the wrong code. If the miles were deducted, I would definitively follow the logic to tell Air France that they have to grant you First Class seat. C est la vie !
Actually same thing happen to me with United miles used on Air New Zealand. Reservation was cancelled but they Air New Zealand gave me a seat in First Class anyway - even if the reservation had been by United. C'est la vie aussi - That's life too
Let us know. I still have a few miles on Delta which I would like to use for a F ticket on Air France. Now that they have merged with KLM, their call center agents could be confused. New rules...new complication...fear of the new manager
But be sure to fight for it and fly F on Air France and let us know how it went. Which Champagne ? Is it duck or goose liver pate ? the wine selection ? Hope they still have this nice Pomerol....and make sure they have the right size pijama for you...Ca c est ce que j appelle la premiere classe -That's what I call first class ....