iOS8.1.3 will not update I have the iphone 6 and it will not update past the current OS 8.1.3

The process gets as far as the terms and conditions screen and will not go any further. 


Have tried turning the phone off and on but still the same. 
Have also done the two button reset but still no joy.
The next solution to try might be to backup/restore your iPhone.

The Apple Store can help you with this, but probably not free of charge unless your iPhone is under warranty.

Fortunately, you can do it yourself, but you'll need to be able to log into iTunes with the same Apple ID that is used to identity you on the iPhone on a computer, and you'll need to be able to connect to that computer using a USB adapter cable.

If you can do that, then here's a pretty good description of the process:

http://www.uberphones.com/2011/05/restore-your-iphone-and-keep-homescreen-organized/.