One can leverage American Airlines Travel Credit to book the air tickets online and offline both. But one should leverage the travel credit before its expiry date. And this could cause them a regret about losing the value compensated during cancellation or delayed flight.
Instead of both procedures, if you are still unable to leverage Travel Credit, you can access alternative options like email to state your concern to the Airline. But make sure to enter your contact in an email. With this, there would be an ease for the experts to call you back.
See: how to use flight credit american airlines