4.4 Once an Award Flight is booked using Points, it may only be cancelled prior to scheduled departure by calling 1-800-JETBLUE, TTY/TDD 1-800-336-5530, and paying a $100 cancellation fee. Points will then be re-deposited to the Member's Account. Points used to purchase the Award Flight will be automatically forfeited if a passenger does not cancel prior to scheduled departure.
You're looking at a $100 redeposit fee and then whatever the new costs are, either in points or cash.