Sagissan,no Ni ssan

I purchased a new Nissan March 2019,in good faith it's a 2019.,Complications arose its registered before, in 2018.(Nissan alleges now,I knew,& accepted an increase of service plan from 3years/90 000 to 5 years/90 000(am I that stupid).Duly complained as matter of process to Nissan Sa.whom to summarise,cannot assist! No matte R how great the car is.i have a trade in loss.lost to the city of Atlantis(no Atlantic Nissan)