Thanks all. An update.

AF have agreed compensation is due, €600, due to denied boarding. They are also covering the hotel, meal and airport taxi costs I submitted.

​​​​​​I posted originally after they had responded to the claim rejecting it, because with the original flight out, although disrupted, my arrival was not delayed. But that wasn't the reason for the claim, and after I asked them to look at it again, and posted here, they promptly replied this morning and have agreed to pay.

Good outcome. Just need the funds to arrive now. Thanks all!