You have a few options:

1. Accept the itinerary as changed. You should be entitled to the difference in miles between booked and flown classes of service, which you can request after the flights.

2. Research on your own (much more reliable than asking AA) what other options in F exist on or around the dates of your travel. If partner metal, same-level award availability needs to be available. If AA metal, NO award availability needs to exist, AA can open up space on its own flights. Then call AA and request to be re-accommodated on the alternate flight with the class of service for which you paid. There should be no change fee for this.

3. Call AA and tell them you don't accept the change in equipment and request cancellation of the tickets and re-deposit of miles. There should be no fee for this.