I had a similar situation with a US Airways Dividend Miles Award ticket for Business Class to Asia. Fortunately, I found out about the 'downgrade' a week prior to my departure when I went to the US Airways counter to have my award issued as a paper ticket. (I wanted a paper ticket just for the security during travel to China).

I came to learn that US Airways computer puts in a business class 'request' to their partners, but the partner must confirm back their confirmation of business class space to US Airways. My business class space was not confirmed by the partner airlines. The USAirways counter agent spent about 40 minutes on the phone with their reservation office, and I was finally issued a paper ticket for business class.

I suggest you resolve this problem with US Airways. And remember, Americans tend to be more straightforward in their communications than some other cultures. What is perceived as a "lie" by an American, may be just an indirect or polite way of saying "I don't know" by others.

Other times, a cigar is just a cigar.....