Only one line has negative tab balance and the other had BYOD 10% discount. Why do I have to pay off the negative tab if I only want to upgrade the other line with no tab balance? Is not the tab tied to one line only? The self-service page does not mention this at all. Now I went ahead to upgrade, was asked to pay off my wife's negative tab balance, and I LOST MY 10% DISCOUNT and the upgrade did not go through!!