I sent 5 emails to and to request listing of my portfolio on the auction page and purchase showcase in the past 2 months. They were sent using the contact us page on their website and direct email. I have yet received any reply about denial or acceptance what-so-ever. Time to move to AfterNic I think.
Yes, they usually answer emails in less than a week. That's why many prefer to give them a call instead. If you submitted a list they will tell you which ones got potential for auction. Try to email a sedo broker directly. The reply will be faster.