Dell India — Unsatisfied from dell service

Website:

Dell.in

I'm kuldip patel from surendranagar, gujrat. I have bought dell laptop 2 year ago. After 1 year i apply for new warranty. Yet warranty was over last month but i put the laptop in the service center for the some hardware issue in on warranty. They say to me the bottom part pp id wasn't match and they can't inquiry for it. They say to me doesn't possible service in this laptop. But i never change the part from another so why they said to me pp id doesn't match??? It's dell misunderstanding. They can't give me regularly answer. How do i get justice. Pls give me suggestion. My laptop was last one month in the service center.
My laptop service tag : jb23t02
Laptop model : insprion 3521