Originally Posted by
JPG3392
If your current RT ticket is non-refundable, you'll be charged a cancellation fee and allowed to apply whatever amount is left to your new ticket. You will than pay whatever the current rate is for your new one-way ticket. This may be considerably more than what you paid originally for the RT.
I believe change/cancellation fees with CO (PMUA used to use old money) are done with new money rather than old. You'll pay the fee in cash and then have the entirety of the ticket value to use to book your new itinerary with.