Bad service from Renault

My wife bought a Renault kadjar at Renault the glen dealership and was told that it has 5 year warranty. Warranty Documentation or terms and conditions were not provided to her. Now the car is having problems with tyre pressure sensor Renault is refusing to fix it saying it's not covered under warranty. I asked them why was she sold the car without warranty terms and conditions i failed to get a proper answer. What make things worse is that I've been told that i must request the warranty documentation because they no longer issue them out.

Marvin