Try to remember what time it happened, because then Seth can look at the logs for that time.
Next time, try this:
Step 1) Find out if a moderator is on (type in "/msg twi" for twigs, "/msg pla" for Play, and "/msg set" for Seth).
Step 2) Bring the moderator in by sending them a message. If no moderator is available, do what you did and tell them to stop. If they continue, ignore them and get a screenshot.
Step 3) If no moderator is on for a while, send a message to the Admin Server by typing "/msg admin" (granted, Seth probably won't see it unless he's watching, but it can't hurt).
Step 4) Send Seth an email by going to the homepage, hitting "HELP", scrolling down, and hitting "send email" or something (it's the first choice). Tell him the names, call letters, time of event, etc...--anything you think will be helpful.
Step 5)-----optional-------Go back in, and if they are still there, see if any moderators have come on. If they have, good. If not, try another Admin message, and then leave.
Step 6) This. The BEST thing to do as a last resort. Come to the forums and tell what happened. They will be found eventually.
REMEMBER.......DON'T PROVOKE THEM OR EGG THEM ON. DON'T EVEN TELL THEM YOU ARE CONTACTING PEOPLE. THAT WILL ONLY GET THEM ANGRIER.