I bought two round trip tickets, Warsaw to Houston, for my then fiancee and her son. Long story short, they didn't use them.
KLM/Northwest both say their policy is no refund. They acknowledge that I paid for the tickets but say they are the property of the persons whose names appear on them. They would issue tickets to new destinations up to one year from purchase but only to my ex-fiancee and her son. (I am a generous man but not that generous.) She has no money so selling them to her at a discount is not an option.