What plan are you on with your 2 paid lines?
I have 2 paid lines for the all-in ONE plan for $80 a month. Last time they ran this promo, I called up and was told I was eligible and they added the free line, only for my next bill to charge me for it. I called up and they said the rep made a mistake and my plan is not eligible, so they removed the free line and associated charges.
I'd love to get it this time, but don't think I'm eligible, and don't want to waste my time "getting it" if it's going to catch up to me next month.