Improperly threaded, poor customer service. - Armaspec Rifter .223/5.56 Linear Muzzle Brake

Ordered this through DVOR in November and got it right away! I was eager to install it on a new build and imagine my disappointment when it wouldn’t thread onto my barrel. I gently tried in on several different barrels and it does not work. I reached out to Armaspec after looking online and finding that this is a VERY common problem with this device. They were at first receptive, and then went radio silent. I want to return the device, but hadn’t heard anything until I sent my THIRD email asking for an RMA or something last week that they responded as not having any of these in stock.