Hmm. I am curious if the device was rooted (even if not by you but before you got it), as that can lead to this problem if you try to do a reset. Also, there are two kinds of reset. One will wipe only some things from the device. The other will wipe everything from the device. I am including below the instructions on how to wipe everything, just in case that is not the one you have done already.
NOTE: Doing this will clear 'all' the data on your phone, so it is suggested you not choose this option unless you have to, or aren't worried about losing anything on the phone.
Be sure you back up any data you want to keep, to a computer or cloud account, before doing the reset.
To "Hard Reset" the phone...
1. Make sure that the phone is actually powered off.
2. Remove your SD card, if there is one in the device.
3. Press the "Power" and the "Volume Up" buttons, together, until you see the start-up logo on the screen.
4. Once you can see the logo, release the buttons and allow the device to enter the "System Recovery Mode".
5. Next use "Volume Down" button to get to the "wipe data/factory reset" option When in recovery mode the "Volume Up" and "Volume Down" buttons are how to can navigate and highlight what option you need.
6. Once you have selected the "wipe data/factory reset", press the "Power" button to select that option.
7. On the following screen, repeatedly press the "Volume Down" button until the "Yes - delete all user data" option is what is selected.
8. Then press the "Power" button to hard reset the phone.
9. If you took your SD card out in step 2, when the device is up and running again, reinsert the SD card.
Once done, if the device wasn't rooted, and it still shows this issue. Try going into your "Settings" then "Apps". Scroll over to the "All" list and then scroll through that list to find "Phone". Tap it and then tap "Clear Cache" and then restart the phone.
Beyond that, then the phone may just be done for.