Source is in my OP
xp first post of the ATA thread. They are working on a sellback option for the tickets to exchange them with gold, but they haven't finished yet. If you bought with Gaia cash you can contact the billing department for a GC or money back refund, this was stated later in the ATA, so you'll have to dig through a few pages.
You will be the one who gets refunded gold, since you have the ticket. You won't get refunded GC because it doesn't appear in your billing history. Your friend won't get a GC refund because they don't have the ticket.
Tickets will get a sellback option, with a set amount of gold, doesn't matter if you got it by trading or MP.