The City of Toronto is no longer responsible for bus shelters; for issues with them such as this one you can contact Astral Media at 1-866-827-8725 or quality@astral.com . An exception is if the shelter is defaced with hateful/discriminatory graffiti; in this case the directive is to call 311.
I'll close this off (you can reopen if you disagree but I'm pretty sure I'm correct. :^) )