Three things you can do. First, try to resolve it directly with the contractor in writing — most disputes are misunderstandings. Second, leave an honest review on their listing to warn other homeowners. Third, for serious issues, contact the appropriate Ontario authority directly — Consumer Protection Ontario for unfair business practices, the Electrical Safety Authority for unsafe electrical work, Tarion for new-home warranty issues, the TSSA for gas or HVAC problems, your municipality for permit violations, or local police for fraud. You can also report the listing to us so we can review it against our platform rules.