Your experience doesn't shock me. They have a nasty habit of "holding" stock for people signing new contracts only because THEY MAKE MORE COMMISSION off of it. Even a current Cingular customer that wants to REUP their contract gets turned away becaue they want to hold stock for the customer that make the REP the most money. That's shady and needs to stop!
I suggest you report the rep to the manager and report the store to Cingular's district office then buy the phone at another store that doesn't blow smoke up your a$$, order it online or over the phone.