My wife and I are booked in WT+ from PHX-LHR on 15th Apr.

When we booked the aeroplane was due to be an A350, and we pre-paid for a window & aisle pair of seats - 24JK.

BA emailed us saying due to "operational reasons" we have been switched to what looks like a refurbished 3 class 777-200. However our seats have been moved to 18DE, a middle and aisle pair. The seating computer seems to have given others window pairs, so none are available now.

Clearly moving a couple from a window & aisle pair to the middle seats isn't a like-for-like seating offer. Do I have any come back on this with BA?

I would at least expect a refund of the seating charges.