Hey there Moorecheese,
Thanks for reaching out to Apple Support Communities. We're happy to provide some assistance.
It sounds like you have taken some excellent steps already. To help further isolate the problem, we do recommend following any steps you have not tried in this article that relates your issue:
If your Apple Watch won't charge or it won't turn on
Get help
If you use a third-party charging stand, use the charging cable that shipped in the box with your Apple Watch.
If your Apple Watch won't charge or you see a message on your watch that charging with this accessory isn't supported:
Make sure that you plug the Apple Magnetic Charging Cable or USB-C Magnetic Fast Charging Cable all the way into the USB Power Adapter, then make sure that you plug the adapter all the way into a power outlet.
Make sure that you're using the Apple Magnetic Charging Cable or USB-C Magnetic Fast Charging Cable that came with your Apple Watch.
Completely remove any plastic wrap from both sides of the charger.
Make sure that the back of your Apple Watch and the magnetic charger are clean.
Position the back of your Apple Watch on the charger. The charger's magnets align your Apple Watch, and you should see a green lightning bolt 
on the watch face.
If your Apple Watch still won't charge, force it to restart. Press and hold both the side button and Digital Crown for at least 10 seconds, or until you see the Apple logo.
Try a different Apple Watch Magnetic Charging Cable or USB-C Magnetic Fast Charging Cable, and a different USB Power Adapter. If your Apple Watch is out of power, you might need to wait a few minutes for the green lightning bolt to appear after you start charging your device.
If those steps do not resolve the issue, we do recommend contacting Apple directly to investigate:
Get Support
We hope this helps.
Have a great day!
