From the DM partner chart for Virgin:
http://usairways.com/awa/content/div...t.aspx#mileage

It would appear that the only 80,000 point award is, in fact, a mileage saver Virgin "First or Business Class" award. You need to escalate this to a knowledgeable supervisor at DM, preferably an America West employee who is/was familiar with the Virgin partnership.

If there was an error, and Virgin won't release the actual UC seats, then sadly your option is to refund the paid biz tix and redeposit your points (at no charge since it was clearly US' mistake), or take the trip and have one of you sit in premium econ.