You may have gotten one but according to several calls to Three including one an hour ago, you got one by mistake and they DO NOT plan prepaid sims anytime soon. I checked because I am going to be in Europe starting in UK with I hope an unlocked Sprint iphone in a couple of weeks.Just walked into a Three store and they gave me a nano sim and adapter pack, no questions asked. Nothing to pay either.
I do not think the top post shoudl have a confirmation of Trhee prepaid nana when several have checked in stores, and many by phone, and all but one person was told not in in near future