I bought a space gray iphone 6 16gb from the Apple Retal store on Sunday of launch weekend. I used my ATT upgrade. I now want the space gray 64gb and have been looking locally for the last few days. My 14 day return is up this Sunday. If by chance I do find a space gray this weekend, and I return my 16gb, will my upgrade eligible acct show up right away so I can buy the new phone with subsidized pricing? I've heard conflicting info about this.