HTC One M8 Eye won't turn on or charge, what can I do?

[AC Question]

My HTC ran out of battery completely for the first time since I've had it yesterday, so I plugged it in when I got back from work and the screen lit up with the charge symbol. I came back to it a couple of hours later and it was completely dead and I haven't been able to get any life out of it since. I've tried leaving it charging on a different port overnight, using a combination of power button with volume up and down to try and reset it, I've plugged it into a computer and it didn't register it at all, and I've removed the sim and sd cards and tried resetting again. Is there anything else I can try???