Duplicate Content URL's

Help! Need advice

[talismon]

We recently submitted to site match through a reseller and got some great positioning for our domain name on major keywords. A week later we were dropped! After some investigation I realized that we had two urls in Yahoo directory and both have our site (duplicate content)

I need advice on the best way to remove the duplicate url so our dname can be re-indexed. Is a 301 redirect the answer or should I try and get Yahoo to drop one of our url's. Problem there is it is nearly impossible to get in touch with someone at Yahoo site match b/c they are understaffed - or so I'm told.

Does anyone have an alternate solution?

Thanks