I have tried to change my email address but cant sign in to change it as the site will not except the new address. To get around this I started a new account only to be informed that I cannot now play the game that I have paid good money for as the key number has been used before. I paid for this game and now it is useless to me. Does anyone how to get around this?
Contact Blizzard support. You definitely can't just create a new account and try to apply the CD key from your first account - it has already been tied to that account, and that's how they prevent multiple installs from the same key. You will need to get your email on your primary account changed and if you haven't been able to do it through the site you will need to contact Blizzard support and wait for them to get back to you.