Won't turn on - Falke LE 1x33mm 65 MOA Circle/2 MOA Dot Reflex Sight

Bought it on DVOR for a future build. Worked just fine when I took it out of the box, then it sat in the safe for a few months. Fast forward, build is complete, go to the range, it turns on, then......dead. Figured battery was bad. Came home, tried FOUR different batteries, all brand new. Nothing..... DVOR won't do anything about it and FORGET getting a response from Falke. German company, but these are made in China. Garbage...