Did he make a typo?
Or does it say 2013 on the box as well?
There's no expiration date for what he's talking about listed. There's a bit regarding the codes that lists March 2013 & November 11, 2012 in regards to the free month codes being valid. Anyway there's no August 2013/12 listed anywhere in the packaging.
Also no, "while supplies last" anywhere.
I'm on the phone with a very nice guy right now. For future reference don't use their email support. Their phone service people are fantastic though.