Wondering why you can't log into the game? Mr. Chilly knows why. It's because you spurned him. He was ready to be your bestest bud, and look what you did. You missed the deadline to get Mr. Chilly express-delivered to your mailbox by merging your WoW account into a Battle.net account. You had all the time in the world. You made Mr. Chilly cry. And now you can't even log in! Serves you right!
Well, it's way too late to reconcile with Mr. Chilly, but you can at least get back into the game if you go and create a Battle.net account now. Remember that, aside from being forced to do it now anyway, this also conveniently organizes all of your Blizzard game accounts into one place, lets you re-download any game for which you lost the CDs, and, uh, has a neat menu, I guess. Just go do it so you can play.
Your mother and I are very disappointed in you.