Here's the link on how to switch the store:
http://kobo.zendesk.com/entries/3684...rders-us-store
Here is the text from that site:
The issue:
A shipment of US Kobos have been mistakenly sent to several Chapters and Indigo stores and a number of them have been sold.
These Kobos can't access the Canadian Kobo site, only the Borders US site.
Solution:
1. Download and install the Kobo desktop application from kobobooks.com/desktop
2. Synchronize your eReader with the desktop application
This will fix the issue.