There's this super idiotic and deceptive policy Verizon has when it comes to upgrading a device you bought on promo with installments.
Basically, if you upgrade and payoff your phone, you lose your bill credits. Here's how the Verizon scam works: you become a new customer or buy a new device under the impression that it's a deal, (like half price for example)... But in reality, the contract for the device is for the full retail price. Then they provide a bill credit to offset the promo price, so it seems like you really are getting the device for 1/2 price. However, you're not. Not unless you keep that installment going for the full 24 months.
In practice, it's a prepayment penalty which is illegal unless it's disclosed, but they get around it by not including the discount on the device contract. Sneaky very sneaky.
The reps aren't even empowered to offer something like a free phone case, or a one time bill credit to help soften the blow. Just nope... Sorry you're messed up and that's policy. The reps apologize... But for what? It's NOT their fault some executive that's probably out golfing and sipping on cocktails made up the stupid "anti consumer" policies the reps adhere to. They're just doing their job and trying to get through one more torturous day.