In my overall experience dealing with AT&T, ,most of their employees are incompetent in handling advance Smart Phones and most of them do not have basic understanding of basic smart phone features. When I told one of the AT&T sales rep that I used my own SIM card instead of the one that came with the device he was very surprised that it worked and he insisted that the iPhone will not with any other SIM card other than the one that came with it. They are not aware that all SIM cards are standards and since the iPhone is locked to AT&T as long as you have an existing AT&T SIM the activation process will work without any problems. No wonder why people were having problems activating their phones.
I think it would have been a good idea for Apple to provide a full training to the AT&T sales rep in using the iPhone. In additions, Apple needs to train AT&T in general how to interact with customers. When I walk into the AT&T I feel like I am walking into a mechanic shop. Where, when I walk into the Apple store I feel I am walking into a high tech Art Museum. Totally different experience.