From aa.com, the section on earning miles with airlines, within that the AA subsection:
If you are an AAdvantage Executive PlatinumŽ, AAdvantage PlatinumŽ, or AAdvantage GoldŽ member, you will earn a minimum of 500 miles on applicable routes, except for codeshare services within Hawaii and with rail service operators booked as the AA flight number, which earn a minimum of 250 miles on eligible fares.
Sorry, but I think you were treated correctly.