You can file a chargeback with your credit card issuer. Presuming that it is a US-based card issuer (bank), the card issuer must process the chargeback if it is made within 60 days of the day when the service was not delivered, e.g., the date your requested your refund. That may or may not have passed, but most US card issuers will process a chargeback for a significantly longer period of time, particularly when the goods or services were not received.

For the benefit of others, do not wait on refund requests. This refund ought to have been processed within 14 days (as it was made through a third-party vendor). On the 15th day, start a chargeback and supply the backup reflecting that the ticket is refundable and that the request was made.

Not only are you making an interest-free loan, but you run the risk of letting deadlines pass.