I'm glad you were able to make your case and get your money back. Unfortunately, I had the same situation, only I ordered a control unit for auto-diagnostics. When it arrived, I checked it, visually it was in perfect condition. But when it came to checking its functionality, it turned out that this unit does not work properly. I of course tried to contact the seller. And while I was proving that the unit was not working, I decided to order a new unit, on the site
www.ecutools.eu of the manufacturer in the hope that I would get a refund for the faulty unit. Unfortunately, the dispute with the seller did not solve anything and the money was not returned to me. Of course this is an unpleasant situation, but I learned my lesson.