Consumer Redressal

3 days ago ago i bought a laptop from a local retailer (I had its bill and packing box). And today when checked its warranty on official site, it showing end date of 28 May 2015. I really got pissed off and called that retailer, he is saying he will check into it. then i incidentally checked its update history which is also showing the last update of about a year ago. Now I am Pretty sure that he gave me a used/out of warranty laptop. Kindly help me, what should I do now.