Your Kobo is probably defected and you can get a refund for it - based on whether you've had your Kobo within a year.
I would recommend phoning the customer care service at Kobo.
My Kobo is frozen too, so i phoned them. They asked me a couple of questions regarding my Kobo and i tried re-setting - it didn't work and i tried everything else i could do, nothing worked and i was told to fill out a questionnaire, and once i got that, Kobo sent the place of my purchase an email saying of the problems I've been having. I am getting another Kobo in return, free of charge seeing as my Kobo was defected and is still unresponsive.