Just write a letter. Either via email or snail nail. Detail the flight details, date, reason given for cancellation, etc. Also, include the details of what monies you believe you are out due to their problem. Include lost hotel nights, taxis home and back, parking, meals, etc. It's my experience that when it's AA's fault they will generally come through with something.

A friend was caught up in the recent debacle in Miami and was a day late getting home. He wrote AA detailing additional parking expense, hotel, meals, etc and was given a fair amount in vouchers.

Good luck. Maybe they can pay you with some of the $5 they're collecting over the phone/in person now.