The Ops question appears that QF have made it legal through changing to the 10.30am flight but it is not his/her preferred flight of 11.35. Did you accept the change, if so you cannot change again, as it is a one time deal.

If you have not accepted, recourse would be to phone and request the preferred flight, or to email the address that was in the Spain/MAD situation. You may need to be prepared for a 10.30am flight - it is hard to claim that is very early.

Other option is that EDI is within 300mi and is either 2.15 drive or 3 hours on the train, while not ideal, it may provide you something better than sitting in LHR for quite a few hours.

KF