It arrived back yesterday. Apple say they could not duplicate the problem but it worked at once back here. However I unhooked WPA-PSK security late last week whilst installing a Netgear range extender. Perhaps I won't reinstate it (I live in an isolated area) and this was the problem. Maybe one of the "Apple IT Bod" on phone checks should be to delete security during the test.
Kind of what several of us suggested..........
Normally related to your router and/or settings not the iPad.
Glad to hear you got it working though.