As a buyer who was recently sold an obvious counterfeit laptop charger, it was extremely frustrating to have the seller repeatedly deny it and then ghost me over it. I sent photos of the item and an explanation of how it differed from a genuine product (fonts, etc of writing on the side of it were wrong...). They refused to give an explanation for the differences, instead only repeating that it was genuine. If i were you, i would advise those people to pay attention to what the buyer is saying. Ask the  buyer how they know it is counterfeit

I'm in this situation too. Seller had refused to email me back for over a month after a (counterfeit) laptop charger failed within 4 hours of usage. When I shipped the item back they failed to collect it from post office. I put a complaint into Trademe, and within 10 minutes the seller issued a partial refund that excluded both the shipping i paid to them, and the cost of shipping their piece of junk back to them. Continued to ignore my emails requesting the full amount. So many reasons that this company should just be banned from Trademe.