Have you tried setting the country to "United States" at the bottom of the help page? Live Chat should then be available.
Other than that, you can try their Twitter support during work hours, they've helped me before and really fast:
I tried that already, the "Call Me" button then became available, but not Live Chat, strangely. I'm not on Twitter, but this is as good a reason as any to get on the service, I suppose. Thanks for the suggestion, and I will try to get to them next US work hour cycle.
