Just a few questions...
Check your phones region under "settings"...... Is your phone from your own country / region? or did you buy it from another country?.. Is the Software version on your phone for the country where you live?.
Are you on Standard updates? or are you in the Dev program?
Also.. try rebooting your phone, reconnect to wifi and give it another go?, Always update over Wifi, never use Data connection, even if you have loads of Data or Unlimited Data...
Hope that helps