Q u o t e: It's been a good while since I've played on bnet.
Define "good while".
It's b.net policy that inactive accounts are subject for deletion. If you did not check into your account for about 3 to 6 months you can prolly kiss it goodbye. In case an attempt to log into this account with D2 gives you a "bad password" message instead of a "no such account" reply, someone else re-created it and you are no longer the owner.
Venture to the Realms Beyond to get off the beaten path.