The way the trade up promo worked is they gave you $650 total split between your de riches trade in value and the rest as bill credits. So say they gave you $265 as a trade in credit. This trade in credit can be directly applied to the phone, or towards your upfront fees like taxes (which are not covered by the promo) other accessories, or on your bill. Now, you were promised $650, but they already gave you $265 for the phone you traded in, so they still owe you $385 as bill credits for the next 24 months. That's $16 a month. However you're still financing the iPhone 7 at $27 a month, that means after your bill credit of $16, you're still paying $11 yourself. The iPhone is not directly free due to the trade in credit that you get upfront, you have to request that trade in credit be applied directly the phone if you don't want to have any leftover amount to pay every month. In the end, after 24 months you had to pay $650 plus tax for the iPhone 7, but you got $265 as a trade in value for you 6S and $385 through bill credits, making it $650 you got back total. It would seem your trade in credit was applied to your upfront fees and on your bill instead of towards the iPhone 7 itself since that's not automatic. For future reference, the next time a promo like this comes out that you want to take advantage of, I would recommend that you opt to make a down payment in the amount of your trade in value. This way the charge cancels out once the trade in credit is applied, and all you have to pay that day is the taxes for the full cost of the phone which are never covered by these promos. And then your monthly charge should be the same as the credit you should receive so that they cancel out and it makes it easier to understand.