I can imagine I'd of been disappointed as well.
However someone at the Dallas dealership DID call back and TRY to be helpful.
Sorry to hear you had a bad experience. But I've been to the dealership several times and found all 3 sales ladies and the receptionist to be wonderfully helpful and nice. I haven't actually met or dealt with the parts counter. Have you tried contacting the manager or someone who can do something about the issue such as additional training? When it comes down to it complaining on the forum here is kind of moot for the most part. As most of us are waiting for or have the 451 models. And since there are very limited dealerships ESPECIALLY in the DFW, Texas, Louisiana, Oklahoma, Mississippi and Arkansas area's .... our hands are tied as to what dealership we can use. I'm jest sayin.