Unfortunately AA is within the COC, seats aren't guaranteed, even when they FUBAR things themselves. Sometimes the only way to get them to fix things is to escalate to a Supervisor either when you called them and/or at the airport. Just make sure you have a copy of the original seat assignments when you deal with the higher levels and be prepared to be disappointed again. Given your comments about the male GA's remarks I'd definitely escalate this one if you didn't mention it in your original discussions with AA.

Do you have status with AA or their partners? I've had issues with them that didn't seem to be going anywhere until I reminded them that I was an OWE (LATAM Black) and the attitude went away instantly at the agent level and they found a work around (bumped me off a flight in MCE and were really unhappy when I reminded them that the weren't following their IDB procedures).

Depending on how much you want to raise the stakes you might want to deal with the social media group at AA. You're probably past the PM/DM route but a rather nasty post on the public side (don't put anything like the PNR or ticket info in the post) with the flight information (Flight Number, Date, To/From) along with what you posted in your original post here.

Other option is to send a letter to Doug Parker (the CEO) with all of the information you've put on FT along the PNR and all of the complete email replies and I'm sure that one of his staff will take another look at things, get back to you, and likely do something a little better for you on your next/return flight, at the very least if it gets through the mail room in time. Anti-anybody/thing comments have no place in any customer service organization so Upper Management will definitely be interested.