The product does not work

I purchased a Henrac Tech Ultrasonic Pest Repellent through Takealot. It simply does not work. I have tried various settings to repel ******s and Egyptian geese - and they ignore it. I have sent 2 emails to Henrac asking for advice - no reply. I phoned and had to leave a message. I have never been contacted. I would never purchase anything from this company again