#11 - July 17, 2010, 2:08 a.m.
I'm sorry that you are having trouble getting through to our Billing and Account Services department, Elviscerate, accounts usually do not just stop working for no apparent reason. There is usually some explanation.
It seems that you are using a mobile Authenticator on your account. Have you tried resyncing it? Usually if you are unable to log into the game and Battle.net account but can log into the forums the issue is that it needs to be resync'd.
You should be able to find information on this process at the following Support Article.
http://us.blizzard.com/support/article.xml?locale=en_US&articleId=27005