iPhone 5 won't turn on or charge- black screen

Hi. I had once used an iPad charger to charge my phone and it got really hot. I then turned it off and haven't been able to turn it back on again. The screen is black; despite trying to turn it on or when charging. Nothing shows up but a black screen.

I had tried doing the hard reset, plugging to iTunes (won't recognize), even different lighting cables. But to no avail.

Does anyone know what is wrong with this phone? I did take it to Apple and they gave some ridiculous percent stating it was not complete dead like .0000001 (whatever that is supposed to mean). Any help would be highly appreciate. Thanks in Advance!