Authentication Key Already Taken

Q u o t e:
Just bought Wrath of the Litch King from Target and I entered the key at Battle.net and it said my Authentication Key was already taken. I've already got WotLK installed on my computer from the 10-day trial, just need the key to upgrade my account. Is this Target's fault or what? Somebody steal my key?

The most common cause of this message is that the key has already been used to create or upgrade a World of Warcraft account. Once an account has been created or upgraded using a key, that key is no longer valid for creating or upgrading additional accounts. If you just got the game and are certain that you had not upgraded an account with this Authentication Key, you should try to exchange your copy of the game at the place of purchase as soon as possible.

Just as if the game were missing a disk or the instruction manual, a copy of the game that has a bad Authentication Key is defective. If the place of purchase is not able to provide you with a replacement copy of the game, you may wish to contact Billing & Account Services directly for alternative methods of replacement.

Billing and Account Services

• Email: [email protected]
  
• Web form: http://us.blizzard.com/support/webform-us.xml?gameId=11
  
  Live Representatives Available Mon-Fri, 8am to 8pm PDT
  For phone assistance please call: 1 (800) 592-5499 || 1 (800) 59-BLIZZARD
  
  • Players in Australia should call 1-800-041-378
    
  • Players in Singapore should call 800-2549-9273
    
  • Players in Chile should call 1230-020-5554
    
  • Players in Mexico should call 001-888-578-7628
    
  • Players in Argentina should call 0800-333-0778
    
  • All other international players should call: (949) 955-0283