Global Resort Services Selling Timeshare Internet, Internet

I used Global Resort Services after they called me and told me that they would sell my timeshare between 2 and 4 weeks max.  That was in 2007 and I paid them $599 up front. I had no calls/offers, nothing since. I lowered the price at least 5 times and still heard absolutely nothing. We are in 2011 and when I tried calling them I got a disconnected phone number "great", $599 thrown out the window. I am now trying to find some trustworthy company that can actually sell my timeshare w/o asking for money up front. No luck so far.