I completely agree with ChrisMoss7. Although IMHO you are entitled to more than the $356 difference between Full First and the Full Business that you flew on that route. The agent should have known better. She must have gone out of her way to force the downgrade, since the computer would have booked you in Premium if she maintained the A class code. What class of service is reflected on you boarding pass? Is it D/J/C?

I would write a letter to customer service demanding compensation. AA has always been forthcoming when they are in the wrong. Also the vouchers that AA gives are valid on all 1-world carriers and can be used on a purchase of your next RTW!!!

Although I have never had this problem with AA, I have had the ChrisMoss7 explained issue when a ticketed 2 class service is changed for a 3 class service flight. In all cases, CX (HKG-NRT) QF (SYD-PER) LA (SLC-EZE) my ticket was issued in D class, but I was still entitled to First. It did take a bit of "discussion" (in the QF case out and out argument) and my guess is that someone less aware would have agreed to the Business Class seat.

Let us know what happens,
rich