Virus-find

First yesterday a program gives me the free security scan. Then i gets a email with the story of my 3months old laptop. Says that he know as best my system because the manufacturer provides it when my laptop was new. Then he putts Norton Internet Security on my laptop for trial, and finds 1 threath/virus. It could be fixed with Norton Antivirus 2015 and take away Internet Security (?????) After research the "virus" was a little piece of the free security scan (first one) also from Norton......... Now i have 1 Norton account with 2 free/trial products, but my "own" security-package expires 21-04-2015. What is going on here?????

Daniel