www.eftps.gov contact

The hostname www.eftps.gov has both A and AAAA records, but the site is only reachable via IPv4. Worse, the IPv6 connectivity is broken in such a way that Firefox and Internet Explorer do not fall back to IPv4. Tracing is broken for both protocols. The 10-net addresss in the IPv4 path were cute. Calling their technical support was an exercise in futility. Supposedly they forwarded messages on to the right people; but the site is still broken after over a week's wait. If someone knows the admins behind the EFTPS website and can forward this to them, the accounting firm for which I work would appreciate it. Thanks,