***They believe the previous owner wrapped a fake device and re-sealed it so perfectly that it looked as if the item hadn’t even been opened. ***
I had that happen with a package of computer printer ink at WM last year. I bought it, took it home and opened it.
I immediately noticed the interior package was already tore open. A closer look showed that the black and white ink was gone, and replaced with an empty colored ink package, then glued back together so carefully it looked normal.
Walmart gave me a replacement for it.
My son used to work at Walmart in the Returs section. He told me tales of customers that would return items they bought. They would show him the receipt and he would check the package. Several times he found that they had replaced the item with a bag of dirt of about the same weight.