I purchased Diablo3 standard edition the other day and loaded it on my computer setting up my battle.net account as it loaded and put in my key when requested. After playing through the first quest suddenly an upgrade screen appeared telling me I needed to upgrade to continue? Thinking it was an mistake I made during loading I uninstalled the game and installed it again following the online instructions. While reinstalling the game it again asked for my key which I entered. I was given an error code saying that the key was already used/ what do I do now?