I would recommend you contact Nissan's headquarters in the US and try to be nice. Let them know you are trying to work things out with them before you start threatening legal action. Legal action should be your last resort. Read these articles for guidance since they had a similar experience like yours.
http://www.thetruthaboutcars.com/201...%80%99t-stink/
http://www.thetruthaboutcars.com/201...on-a%E2%80%A6/