The Insurers are correct that you cannot claim. Under an annual travel Insurance, the cover for the trips is switched on and off at the time of booking and relates to trips covered under the term of the policy. Your policy only covers trips from your home in the UK to countries within the European area. It does not matter that the loss was inside Europe, as the trip and any losses were not covered, as your trip to Canada was not within the terms of your policy.
If you wanted to be covered for the trip to Canada, you should have phoned them at the time of booking to extend your policy.
Have you checked your Home Insurance to see if any cover away from home will cover the loss.