Products not working like it is suppose to and supplier refuses refund!

I bought Fly Repellent Fans, however it seems to be an aftermarket product as it does not serve it`s purpose. I have seen at the Home Expo what it is suppose to do, but the ones I bought does exactly the opposite. I have requested for a refund, however they refuse because it is more than 3 months, however they are not considering the lockdown period. I want a refund for the items that is not working as it is suppose to!