Help me

Hi, I need help on how to get the "back" button on my Zune to work. I have had my second Zune since February 7th.  I had to get a new one, because the other one didn't want to connect to the computer.  So, anyway, the other night I was playing Hexic on my Zune, when it just froze and stayed like that for about 20 minutes- half hour.  And now, my "back" button  doesn't work, whatsoever. So, if you know how to fix this, please help. I appreciate it! Thanks!

Let the battery drain and then charge it back up. If you still have issues please call Zune support 1-877-GET-ZUNE (1-877-438-9863) for service.

Thanks. I've already done that, twice. It still doesn't work. I guess I will have to call. Thanks!