I have just received this email from the dealer:-
"Thank you for contacting us. As far as we are aware, the M9 that was sent to you was a brand new version. However, the issues that you have noted seem to be consistent with an M9 display model. Unfortunately, the only M9's we have left in stock are in grey. I'd be happy to exchange this for you if a grey version is suitable? Alternatively, we can arrange collection and offer you a refund on the M9 black. Please don’t hesitate to contact us if you would like to discuss this further."
So I rang them and spoke to the writer of the email who was very apologetic. I believe that it was a genuine mistake on their part as they have nine stores and obviously some sort of central warehousing so they could have unwittingly sent me a used version.
I have decided that I will wait for the new M instead and because of the good service I've received, I will be buying the M from them with the confidence that if something does go wrong they will be there to help.
I am also now more than happy to give their name out - "Thank you" Wilkinsons Camera, Preston, England