If you bought your ticket with the airline's credit card and have used that credit card a lot you might have some success. We also had to change a return date. My husband called the airline and very, very politely said that we were owners of the airline's credit card, have spent mucho $ on this card, bought the ticket with this card, needed to make that return change.... anyway possible we could be given a break with the change fee?

They were very nice and said they would not charge us the change fee and we only had to pay the fare difference which was $9.

Maybe, if you're a airline card holder, you could give it a try?