blue ticket can be canceled right before the "scheduled departure" for full refund back to travelbank. I wouldn't chance it though, and if you know you are going to cancel, cancel it one day before the flight to allow to website problems, long telephone hold delays, IT glitches, etc. All of which are far too common with this airline.

Hard to understand the your second paragraph, but the policy is here:

https://www.jetblue.com/help/changes...ns-and-standby

• If you cancelled your flight before the scheduled departure time, and are no longer travelling, all extras (seats, bags, priority security, etc.) will be automatically refunded to your original form of payment.