If I had to guess, it is probably in their fine print, and the ability to pay for a refund would be a further refutation in a chargeback case.
That the ticket could not be sold via their system for whatever reason, is not a 'simple' act, although TBH maybe they should write to the DOJ or whatever... given some of the other stuff they've been caught doing, it would not at all surprise me to see some `if (!ticket.HadRefundOption) throw` hidden in their sales system.
TBH OP (Not a lawyer, not legal advice) you could always try small claims, they might not even show up and then you can collect a default judgement
