Another avenue of contacting them is through https://getsatisfaction.com/kobo
I know some have gotten better results that way instead of email. I've heard calling gets the best results.
You can also try emailing KoboExecutiveCare@kobo.com
or try finding email addresses for some of the Kobo exec's
although I did that once and didn't get any better service even though they were going to 'look into it'.
Kobo CS for me has been hit or miss, generally miss.