Booked (via a TA) a bargain basement CW flight to Vancouver in August. However I now I could really use returning a day later. TA inform me the fare's not changeable - at all - fair enough, but will this change at all after I've left?
Whenever I've urgently needed to put a flight back a day post-departure in the past, I've usually managed it - is this worth a shot? Or will BA probably tell me, forget it, you need to buy a one-way ticket home the next day?
Edit... for what it's worth, the Sunday flight, which I am on, is probably busier than the Monday flight.
"Not changeable" means just that. The only option BA might offer you before departure is to upfare - maybe.
After departure, well, you could always go to the airport on Sunday to check whether they are looking for VDBs, or whether they have potential full-fare customers on a waiting list for Sunday vs. empty seats on Monday. But it's a long shot.