Yes, I have tried multiple chargers and other batteries (including an Anker one).
:-(
I assume that means that nothing is lighting up when you plug in the charger?
Since you have tried multiple batteries, I assume one of them had at least some charge at one point. You could get an external charger and make sure a battery is fully charged and try that one, I guess, but it seems unlikely that you have only tried fully-discharged batteries.
Without a battery connected, absolutely nothing happens on the Note 4. If you know for sure you have put a battery in that had SOME charge and still got no response, it sounds like the next most likely diagnosis is a failed connection between the battery and the motherboard.
Pull the battery and check the 4 little gold bendy pins to make none of them are crushed, collapsed, or corroded. Gently push in with a finger to make sure they flex just a little and flex back (we're talking very small amounts of movement here). VERY GENTLY give them a light scrape with a fingernail or plastic spudging tool or something to make sure there is no foreign matter insulating them from making good contact with the battery.
If those are bad, they are soldered onto the motherboard, so you are looking at a non-trivial fix.
Edit to add: Step 11 of this Fixit guide has a good picture of the battery pins - as you can see they are soldered onto the motherboard, so it'll be hard to find replacement pins and unless you are good at microsoldering it's going to be a tricky fix.
https://www.ifixit.com/Guide/Samsung+Galaxy+Note+4+Motherboard+Replacement/38884