contact for opentransit.net (in USA)? about DoS attack

i have a UDP flood going across an expensive international link (to .pk).

between the source and destination, i have bbnplanet/genuity and
opentransit.net (and a few others whom do not respond or don't have
easily identifiable NOC's).

i've opened a ticket with genuity, but would like to get ahold of
opentransit.net, as they would have a better effect.

Please contact cspi@opentransit.net or noc@opentransit.net