my ipad mini has turned off and wont turn back on..and yes i have been charging and pushing the home/sleep button (btw..it was at about 39% charged when it shut down) and i never updated to the IOS7
Try to connecting it to a computer and hold the power/home button together and see if iTunes detects it in recovery mode. If it does, you can restore it from there.
If you follow these steps to go into device firmware update once tethered to iTunes and seen by iTunes as noted above, It should be able to detect in this mode and load a fresh copy of the software.