Originally Posted by
corporate-wage-slave
If you go into Manage My Booking for the hotel, there should be an attachment there with a BA Holidays 24 hour number on it. Usually they will see what they can do to keep your break in place, but after "significant changes" I think you can ask for a full refund. The terms and conditions gives an example of significant changes as "your departure times or accommodation occupancy periods by more than 12 hours.
Thank you for such a prompt and informative response CWS! By some stroke of luck I phoned up whilst in the queue to talk to the rebookers and got put on the later flight tonight which should leave in an hour. Here's hoping..!