Effective January 1, 2016, if you have purchased a 'free to change' economy class ticket and you don't make your flight ('no show'), you’ll no longer be able to obtain a refund.
However, within a period of 96 hours of your original flight departure time you will be given the opportunity to rebook your ticket. In such case you’ll have to pay a penalty of AED 365 plus any difference in fare.
Please note that in the event that your ticket is not rebooked within 96 hours of your original flight departure time, your booking will be void and you will not be entitled to any refund.
To rebook your flight, please contact their customer support team by phone or email.
You can also visit the nearest flydubai travel shop. For more information, please read about their fare types and conditions of carriage.