For some reason, AA still has city ticket offices in Brazil. There is even one directly across the street from my front door in the Copacabana Palace Hotel and another in a commercial building in Ipanema I often go to for diverse reasons. There may be other offices as well, but I never had to research the issue.

Here's the downside: no 800 number for reservations. You have to use a 300 number, charged just slightly less than full long distance rates. But, you can always use the US 800 number over an internet phone service.