I suspect it's just an artefact of the HHA - the computers haven't got the full logic to reapportion the refund correctly any more. There have been a lot of changes with the move of ownership to AGL I generally do get the online / immediate refund on cancellations, not that I use it too often. Maybe that's part of your solution here, try to reduce the number of cancellations she does, and/or creating a bigger buffer of Avios so that the back office route isn't problematic?