In the interim I was contacted by Nikon's South African distributor.
they have checked and confirmed that the camera has not previously been sold, registered or repaired on their system. also confirmed that it was delivered from their new stock to the retailer on the same day that it was packaged for shipment by retailer to me.
I was offered a new camera in exchange at no cost but decided to keep the one I already have to avoid the inconvenience. It has no detectable faults or wear. A superficial check for the left focus issue has not showed any problem. I will conduct a detailed check when I have time over the weekend.
Have to give credit to the local supplier for their rapid response to my e-mail and their unconditional offer to replace the unit.