Has it ever gotten wet? Has it been dropped recently?
A lot of the time the charging ports will break on these things. Does the actual port look okay? The flat plastic "nub" inside the port should be flat, not mangled up.
Does the device get warm at all when it's on the charger?
If you're around a Batteries+Bulbs, give them a call and see if they have a battery in stock for your device. Unfortunately, your phone doesn't support wireless charging as far as I can tell, so you wouldn't be able to simply throw it on one of their chargers and see if it works.
Unfortunately, there's little I can do over the internet for a no-power issue. Normally I'd recommend taking it into a shop, however most shops don't have the expertise to repair what could very well be a board-level repair job. At the very least, you could try finding a place that does free diagnositics and having them open it up and inspect the device for damage.