We have an Avios booking in CW using a Chase 2-4-1 voucher. We will take the outbound flight but our plans have changed and can't take the return flight. There are no CW seats available on the date we can travel and the ticket will expire before we could ever use it for a future return flight. What are my best options for possibly getting the taxes and carrier charges refunded (I realize the Avios are lost)? 1) Call and cancel the return portion (and incur a service fee) or 2) just no-show the return flight? Thanks for any advice.