Bit of a dilemma.

Not a very frequent flyer on BA so unaware of what will/could happen.

We have WT+ from IAD to LHR (on 4/23), the aircraft was the 744 High J. Paid to choose seats.

Just noticed an aircraft change to a different 744 with WT+ seats from rows 28-31. The seats we originally paid for are not available. The only ones left are middles.

My question is: what will happen? Are we stuck in 2 middle seats, will they at least refund the cost of the seat choice? Can we urge them for an upgrade?

My thought is to NOT do on-line check in and deal with it at the airport.

help...