Hello - just for more clarification, which iPad Mini do you own - 4 models have been released since 2012 (see
HERE, if uncertain) - you are on the most recent iOS release, i.e. 10.2 - did your problem start w/ an upgrade to iOS 10.x - this would be pertinent if you have an older Mini model.
Also, did you do a 'Reset' properly - hold down both the ON-OFF & HOME buttons simultaneously until the Apple logo appears (may take about 10 sec), then release and allow the device to reboot - if not done in this manner, then try again - let us know your results. Dave