With USAirways you can only apply non-refundable tickets towards other non-refundable tickets. Hence no way to get your money back after its tied up in the system.

Side, but related story, I had two non-refundable tickets through two different agencies. One agency applied the difference in the value towards the change fee. That's what I expected. The other told me that 'the airline mandates the $75 change fee and you lose the value difference in tickets'. I told them bullsh**, and then they told me something about corporate policy, and then they started stumbling over themselves and hanged up on me! .. grr.... I hate corporate mandated travel agents. They know I can't switch so they treat me like crap.