@all you may save this breakdown to explain how the trade in promo works

$XXX  Promotional Credit
- $XXX  Trade in value of (trade in device) that will be injected on the bill
= $XXX

$XXX/24 = $XXX

$XXX  regular EIP monthly
- $XXX promotional credit
= $XXX  monthly chare of (device to be purchased)

Please save this spiel : 

When you trade in your device,  you can get up to $XXX discount via bill credit. The fair market value of your trade in device is $XXX and this would be credited on your bill as one time lump sum, then the difference from the promotional value which would be $XXX would be credited monthly for 24 months. So, you would have a $XXX discount monthly on you equipment installment plan.