Just a reminder they updated their terms awhile ago:
http://www.bestbuy.com/site/gamers-club/gamers-club-unlocked-faqs/pcmcat341800050017.c?id=pcmcat341800050017&ref=P30T23R146&loc=BODY&CampaignID=793258&SubscriberID=111938546&eut=2428686424
If you bought one recently, I would def try to do this in store. They dont specify how this is done in-store...just online.
http://www.bestbuy.com/site/clp/free-samsung-gear-vr-offer/pcmcat748301719563.c?acampID=0&ref=8575135&loc=0&id=pcmcat748301719563