I have recently been finding that my BA flights have less than a 50/50 chance of ever being posted, even when the AA# is right on the boarding pass and, thus, obviously in the PNR. I routinely mail the boarding pass and copy of the ticket to AA and within a week or two receive the credit. Oddly enough, a few days after I receive the credit, I get a postcard saying that they have to check with the other carrier and it may be a while!