I had 2 GA tickets, put in my billing info, and then I was slapped with an unknown error page. I tried and tried, but nothing was working. Finally, it locked out my password, and I was left with no tickets. I immediately called Ticketmaster, and they told me there was nothing they could do, and I had to contact U2.com. So I found a phone number for U2.com and called. I spoke with a guy who probably wasn't too excited to be receiving phone calls from fans. However, he said this was entirely in the hands of Ticketmaster, and there was literally nothing he could do.
As I felt my awesome GA tickets slip further and further away, I called Ticketmaster back. This time, I spoke with someone in the pre-sales department who knew about the problem, and transferred me back to customer service. I waited on hold for 18 minutes. Finally, someone picked up, and she said that everyone was reaching this "dead-end." She promised they were working hard on the problem, and that someone would call me as soon as things were working.
I'm certainly not holding my breath.