#0 - Jan. 22, 2007, 9:26 p.m.
Blizzard Post
We are currently working on a solution to assist customers who upgraded their World of Warcraft account with the standard edition of Burning Crusade and have since purchased or received a Collector’s Edition and would like to “re-upgrade” their account.

If this describes your situation, please call our Billing & Account Services department (800 592-5499)and be ready to provide the following information: Account Name (and ability to fully verify account), claimed Standard Edition BC Key, unused Collector’s Edition BC Key.