Flew TPE->HKG->LAX last week and was originally booked in PEY (class E) for both segments. After arriving at TPE airport I was told my original flight to HKG would be delayed and they would place me on an earlier flight. The earlier flight did not have PEY so they put me in business class.

Few days after the trip I noticed the TPE flight never credited to my AA account. Checked my booking on CX website and it says I was put in economy class with a M class ticket (no AA Milage credit). However, the bottom of my boarding pass clearly says J. And of course, I purchased an E class ticket.

My assumption was that regardless of the class of service flown, I am entitled to the miles for the class I paid for. Is this correct? And should I fight back to get what I am entitled?