CRNA, seems like you need to put two and two together. Ebay store, not working, Bushnell will not warranty it? It seem they think it may not be a Bushnell. From what little I have looked on Ebay for optics, it seem to be a lot of junk being passed off as good stuff. If yours will not work to 500, that is the first I have heard of from a Bushnell. They have been one of the more reliable ones out there. I hope you haven't bought one of the Fake Leu. mark 4s also.