Nissan rusts after 18months being bought brand new

I bought a brand new off the floor NP300 hardbody from Nissan Milnerton in Nov 2016. It's the 2.5TDI double cab.

Besides other issues, I have recently discovered that both front door hinges are rusting - not Slightly, but rather badly.

I took the Vehicle back to Nissan and reported the rust to them. They booked the vehicle in for a day and took it to a panel shop (as far as I know) which took photos and compiled a report. They returned the vehicle and told me that they would send the photos and report to Nissan South Africa and revert back to me as it would be covered under the paint warranty.

Taking into account the vehicle is only 18 months old and was bought brand new, I can't understand how it is that both front door hinges are rusting.

After following up several times over the last month, I eventually got a call today informing me that Nissan South Africa is not covering the rust and that it was caused by outside factors.

I can't believe this, and why are the external factors only affecting the hinges of the front doors......

I will be taking this matter further and let everyone know how bad the quality of Nissan vehicles actually are...