GuildWars EotN Argentina

Hi there guys.. As the title says im from Argentina and im trying to play EotN. the thing is that on the retail stores here, it sold out and there wont be any kind of reposition. Anyone here is from Argentina and knows by chance how can i aquire a copy of the game. Thxxxxxxxxxxx
PD: Im not able to do it by credit card as my card is National only. Meaning im not able to purchase services outside my country..