Unable to activate Iphone 6, either through wifi, mobile or ITunes

Hi all,

hopefully this is an easy fix, but we have just handed down my wife's Iphone 6 to our son and we can't seem to activate it (it worked perfectly several hours ago for my wife). We went through a full erase and reset for our son so that he had a 'blank canvas' for the phone. However we are now unable to activate the phone when running through the setup process. I have tried activating through wifi, mobile data, and ITunes, but none will work (all with varying error messages). I have also tried to do an automatic transfer (and setup) from my wife's new Iphone, hoping that we could get it up and running and then just delete her apps, icloud etc so that it looks like a new phone., but still no luck!!

Any help you may have would be greatly appreciated.