Let customers release or transfer tickets they no longer need

What specific challenge or problem does this idea solve?

Our customers often buy tickets for multiple shows to see their children perform and then decide not to attend some nights. It'd be nice for them to be able to mark that they are no longer attending (and get a refund, but we'd still like this even if they can't get a refund), so we can then open the tickets for other to purchase.

How should this work?

Who will benefit (Admins, Staff, Students)?

How will this change impact your daily tasks or overall experience?