So I have the old AT&T family plan unlimited. I just placed an iphone 5S order for the main line. No problem. Now when I try to place an order for the secondary link at the apple website, I get an error saying it can't do the eligiblity check. I checked both lines a few days ago, and both were eligible. I log in to my AT&T account, and it says that the main line (which I just ordered a new iphone 5S for) is eligible, but the secondary one isn't. Any suggestions on what to do so I can upgrade both my lines?