Hi Sounds as if your KT has a problem.
I had a problem with my first KT. Kobo and my retailer (Asda) were brilliant. Said just exchange it!
You can ring Kobo help from UK Toll Free Kobo Help Line, UK 00800 33 22 33 44.
Or I'm sure WHSmith would help.
Brilliant device but if you have money to waste don't throw it in the bin I'm sure someone on the forum would sort it with the purchase receipt.