no feedback and very poor service

my son Jonathan bought a Nissan hardbody from the above supplier last year Oct.. firstly I have been battling for a year to get the service book and spare key out of them.. then when my son went to take out the licence disc to be renewed it was brought to his attention that this vehicle that was financed through west bank is not on the road.. have contacted the above dealership numerous times with just no luck.. what can I do in this regard..Please help my sons Name is Jonathan Van GENT