Try to search "Kijiji Canada" in a browser and go from there.

I exclusively use the computer for kijiji;
I observed it making my phone heat up, and I have understood that this app is TERRIBLE for data mining.

I actually noticed it picking the wrong location (it doens't help that I continually deny it's request for my location), but you should be able to click on the little arrow thingy to the right of the search bar, and make a location based on a postal code - that's what I recall doing.