Q: Performed a reset on advice of Apple and now wifi is greyed out

For the past two hours I've been trying to sort this iPad out.  I'm ready to throw it!

I took it to the Apple store this morning because the battery has been losing power quickly (from 100% to nothing in the course of a day without being used).  They ran diagnostics and told me the battery was fine.  Advice was to update to latest iOS (was on 9.2) and to reset,  try that for a few days and if battery issue persists to return it.

So I came home, updated iOS, reset it and thats when the issues started.  First issue is "Verification Failed - there was an error connecting to the Apple ID Server" which I'm presuming is because it won't connect to the internet because the WiFi button is greyed out and won't turn on and off.  I've tried a network reset and another hard reset.

Any ideas?  I really don't fancy another long drive to the Apple Store (I live in Abu Dhabi) for them to fob me off again.