Ticketmaster contact? - out of options

Is there anyone from Ticketmaster on list, or can anyone provide me with a decent technical contact? I have tried their "Global Monitoring Support" organization by phone and by email with little success. We have several thousand users NATing behind a single IP address. Ticketmaster is blackholing this IP on a regular basis, presumably due to volume of requests. If we change the NAT, the problem quickly crops up again. Their GMS support team has supposedly fixed this multiple times, but in fact have not. Any suggestions? thanks -Steve