I was just denied because the site was "ineligible"
Hotel: Tropicana Las Vegas Doubletree
Dates: March 16-18th
Hilton Rate: $132/Night
Prestigia.com Rate: $87.60/Night
All I got for my troubles was a message in the e-mail saying that prestigia.com is ineligible. No explanation on why it was ineligible. From what I could tell the terms of the rate were the same. I will be canceling my Hilton reservation if they don't match the rate.