Screen of a watch not working.

I bought two watches from PMC, one of the watche died on second day after receiving it. I have been sent from piller to post since that moment.i have wrote numerous email but still no solution. The watch is K37 1.32 inch heart rate monitoring smart watch with GPS positioning. O separate emails the asked me to take photos of my watch, that i did. On second email they asked to take a video of the watch, which I did.On 3rd email they asked me to take video of the watch while changing it, and I did that too. 4th email they said I must again take a video of the watch while charging. Even now there's no respond from them.