To use JUMP the phone has to be working and in good order so you would have to use file a claim and pay the deductible. With that being said though with only $99 left JUMP really isn't that great of a benefit to you since you have to turn in your old device which would cost you your deductible to turn in. Frankly what I would do is look up the value of or what you could get for selling your 7 and if it is more than your deductible +99 then file a claim get the replacement, pay off the $99, get the phone unlocked and sell it or keep it as a working spare but I wouldn't use JUMP either way. You could just pay off the $99 and be done with it and start a new loan plan. The only wrench in all of this is, that if you are on the original JUMP I would make sure you can just start a new EIP on that line and keep the original JUMP.
Just checking in to see if you need more help. Please let us know. Thanks.