Just as I predicted, it is AT&T, not iPhone

Just as I predicted, my activation is not smooth at all.
My previous rate plan is not compatible with iphone services, so at&t silently kept me in the waitlist for more than one day.
Glad that i asked around everywhere. Here is the highlight of activation:

1. You need to have an elegible plan to get activated. If you were existing customer and want to add $20 for network access, it is likely that your current plan is not compatible to the iPhone plans. Be careful and ask around.

2. AT&T activating your SIM card does not mean your iPhone is activated.

3. Apple need to receive AT&T's order complete message, then Apple will "activate your iTunes."

4. After your iTunes is 'activated', it remembers your account information. Anytime you sync a new iPhone to this computer, it will ask you if you want to activate it as yours.

Anyway, it is good that finally I activated my iPhone, and here is a picture of Coldstone icecream cake picture taken by iPhone.