Poor aftersales service: Natis

I purchased a vehicle from Webuycars on March, 4th in a cash. I was advised by the sales person that the NATIS would be received within two weeks. Next week will mark almost a month not having received the NATIS. I am currently driving a vehicle for which the license disc has expired a year ago and I run the risk of receiving a ticket if stopped. When I queried this with we buy cars, I was told to just accept the ticket and we buy cars will pay for the ticket. How is all of this acceptable? One cannot be paying for a car without having received the proper document and not being kept up to date on progress of the vehicle registration process. LESSON learnt when buying a car.