Can I sanity check a recent compo outcome with those in the know please? AMEX 2-for-1 booked in F with Avios. Straight Avios booking. Outbound all fine. Inbound LA A380 flight cancelled 24 hours before departure as went tech and rebooked to a flight 4 hours earlier and also put into J (no F seats available).

BA were quick and proactive in paying 2 x £280 in cash for the EU261 cancel. They also refunded 75% of the Avios paid for the inbound so more than just the difference J and F. Finally 2 x £24 were refunded presumably the tax difference between J and F.

Question - shouldn’t they have refunded 75% of the taxes and fees of that sector, for which we paid 2 x £900 in total (so 2 x £450 as only one sector)?