Got my gold iPhone 6 Plus and find it just a bit too big. Stopped by the AT&T store on the way home for cases and saw the regular sized Space Grey on display and fell in love with it. But of course impulse and curiosity got the best of me with my new gold phone waiting on my doorstep and I opened it, activated it, and tried it out. Am I now stuck with it? Anyway I can sell it and order a new regular Space Grey since I already have activated it? Does anyone know how this works? much appreciated!