Reviving this old thread as I won’t be able to use a $550 ticket (of which $122 are taxes). How do I get the tax part back? Do nothing? Cancel and ask for a refund? No-show and ask for a refund?

It is a non-refundable one-way ticket with a travel date in a few weeks.

I guess the fair way is to cancel and request refund but those rules are always complex...
Thanks!