Disputes department ignores emails

I enjoyed using Virgin Money's credit card for the low fees and minimal in-branch interaction. However now that I am disputing a charge, they have not responded for six weeks, despite my four follow-up emails. I paid for a flight on 11 April, but since there was no flight confirmation, I assumed the payment hadn't gone through. When I asked for a statement four days later, but it did not show the payment. A month later, the statement did show the payment, but the airline has not logged the flight. After disputing the charge via the services email address on 16 May, I was told it had been referred to the disputes department. Despite mailing both disputes and services four times since, I have heard nothing back. Dispute reference number: 00D1r1GluM._5001r2GihFU