iTunes Money Gift Problem

My friend got me a $10 iTunes Credit gift in my email, but every time i click redeem, i keep getting prompted to re-install iTunes, so i re-installed it, but it prompted the same thing again. so i tried it on my iPhone, and it took me to the iTunes store, so i assumed that it had worked, but the balance never changed, still that .08 cents... am i doing something wrong? or is it just bugging/glitching.