How to exchange black for white using in store pickup?

[macmisty]

So I purchased the black iPhone 5 online and like many others, want to exchange it for the white. I want to get the white phone by using the store pickup option. Problem is it won't let me do store pickup since I'm not eligible for an upgrade. So, can I do this: reserve the white phone under my husband's account which is eligible for store pickup/upgrade, go to the store and somehow exchange the black phone for the white one that I have reserved under my husband's account? Or would Apple have to return both and it wouldn't work because 1) they can't sell returned items and 2) my eligibility won't be reset yet.