here is what i would do, get in touch with Eileen and tell her that ticket was yours, it cost you $70 and you had intended to get a refund, until the dud you call 'G' gave the ticket away.
she went & no doubt enjoyed herself, if she has any decency she will cough up the cash.
i would also give 'G' a massive 'Who the **** do you think you are' styled verbal blast.
chances are , you won't see the cash, honestly i would wipe these guys, they obviously have no respect for you to do this in the first place.