Welcome to FT.

I am not sure I understand your question, but I'll answer as best I can. Are you asking if you make a change to a ticket, and the change results in a lower fare, will you be given a refund? If so, the answer in many cases is yes. However, beware that in many of the discount fare classes a change fee may be involved. So you will receive the fare difference minus the change fee.

Hope that helps.