According to this website
Ontario Landlord and Tenant Act; questions and answers
If the landlord does not make repairs on your verbal request, or has a history of not making repairs, put your request in writing, including the date of the letter, and keep a copy.
If the landlord still hasn't done the repairs in a reasonable time, then call your city Building Inspector to make an appointment for them to come out and look at the problem. If the inspector won't come then ask to speak to their supervisor. Get a copy of the inspectors report to save for your records.
If you are still having problems getting repairs done, you will want to contact the Investigation and Enforcement Unit, at 416-585-7214, or outside of the 416 calling area, toll free at 1-888-772-9277.
If problems persists, then you may want to contact your lawyer or Community Legal Clinic, City Councillor, and maybe even apply for a rent reduction on the basis of lack of repair being a reduction of services in your apartment.
