Re: am i gettin ripped off?
Far as the card itself goes, you definitely should contact the reseller immediately. Based on the product description and picture, you definitely should have received a 5900U. It also should be noted on your receipt/invoice that the Ultra is indeed what you ordered.
That said, the points Rob brought out for the X800 Pro ($399, by the way) and 6800 should be taken into consideration. The X800 Pro can be had now, and the 6800 should be shipping within the next couple weeks (if reports are to be believed). If those cards are out of your price range, consider the 9800 Pro as those can be had for about $200 and they offer superior performance to even the 5900 Ultra.
If you want a good interim card, consider picking up a 5900XT. That should last you until the 6800GT/Ultra cards start dropping in price.