AAdvantage customer service will normally give you the information you need. Often they can post the miles directly if you have the receipt with the proper ticket number, etc. For foreign carriers, they follow the same procedure, but they put in the request to the foreign carrier for you.

A few weeks ago I had a LAN trip that didn't get posted. The agent took the info and submitted it. She said it would take "up to a month." It posted in about a week.