Originally Posted by
AADFW
From what I understand (someone please correct me if I'm wrong here), you will need to call them and cite the upgrade T&Cs as mentioned above. They will probably need to look up that upgrade transaction via the cancelled ticket number. Also, you will likely be put on hold for a long time while they look into the rules, just like I was. Finally as noted via the link above, if yours was a same-day upgrade, evidently those really are completely nonrefundable.
My experience with the two AA Central Reservations agents made it abundantly clear that the trip credit issuance policy for online promotional upgrades has NOT been well communicated to the rank and file to this point. Although only speculative, this might be by design -- meaning that perhaps AA management wants passengers to request the trip credit to which they are entitled under the official rules rather than doling it out automatically upon each cancellation.
Quick update here based on a more recent experience. Whenever you buy the promotional upsells, you should receive an email receipt that will include a "0115..." number referencing the transaction. Once you cancel or exchange the associated ticket and need to refund the upsells (or get a trip credit), you simply go to prefunds.aa.com and enter that 0115... number. After a few days the refund will process. This is much faster and easier than trying to do it through Central Reservations.