Just to close this story off and it has a happy endingThey did notice it had a very slight bend (Iphone 6 issues) but like myself could not believe it caused the fault and send it off to Service+.
-Avoid ever getting an iPhone (well that was never going to happen anyway) :-) The experience was just too traumatic
Iphones are prone to bending (google it for the 40 million pages of phone bending stories) so that is a fault in itself. You could successfully argue that it is normal for people to put phones in pockets. So ,apple should cover slightly bent phones for making them like that.
Louis Rossman has covered iPhone bend problems several times on his YouTube channel. Apparently it doesn't need to be an obvious bend, the damage is done by repeated flexing of the motherboard. Contacts under certain ic's break off from the board tracks.