Last august, I flew from SFO to SIN via HKG on a codeshare AA/Cathay Pacific flight. I thought that I'd gotten the AA code, but I suppose that I must have gotten the Cathay code instead.

At HKG, on the way to SIN, an AA employee approached me and asked if I would be willing to switch to an earlier flight as the one that I was booked on was oversubscribed. I agreed and switched.

When I got home, the return trip (SIN->HKG->SFO) posted to my account, but the trip out did not. I submitted the trip through the AA system and a few weeks later, it came back as denied. I resubmitted with a faxed letter of explanation and it was denied again.

All of the flights are of code levels listed on the AA website as eligible for mileage credit from Cathay. The return trip which was credited automatically is of the same code level as the trip out which was not.

Who can I contact to get this cleared up? Do I try to go further up the chain in AA or do I contact someone at Cathay? Is there a list somewhere that shows who to talk to?