iMac OS X Lion update

i have purchased iMac on June 2011, but i would like to update my iMac to OS X Lion.

i asked one of the Apple Staffs in 2011 Summer and he told me that i can update OS X Lion for free of charge after it releases. However, few days ago, I asked one of the staffs the same question but he told me that I have to purchase OS X Lion from Mac App Store and cannot update it for free.

So, can I get OS X Lion for free of charge if I purchased iMac on June 2011?