IPhone 4S activation NIGHTMARE, Apple problem, not AT&T

Question

Got new iPhone 4S delivered on release day (Friday, Oct 14).  Activated without problem.  On Sunday, it quit working except when connected to wall charger.
On Monday, called AppleCare, hardware failure was problem.  Had choice to pay $29 for them to immediately send me another one, or, they would send me a box to mail in my broken iPhone, then they would send me a repaired or replacement iPhone 4S.  Opted for latter.  Drove 40 miles to AT&T store to get new SIM card for old iPhone 3GS, activated it in store.  Got shipping box for 1st iPhone 4S on Tuesday, mailed on Tuesday.  Got replacement iPhone 4S on Thursday, late in day.  Replacement was quick, no complaints.
Nightmare Friday:  ready to activate replacement iPhone 4S, about 5:00 PM called AT&T Business from my office phone to activate, had obtained IMEI & SIM card nos. from screen on new iPhone 4S.  I noticed, however, that the IMEI no. on the phone was different from the IMEI no. shown on the shipping box that replacement iPhone 4S came in.  Initially, the process went smooth until the time came for phone to actually activate.  It wouldn't.
After going through initial menu on iPhone to activate, I end up with message:  Device unknown   This iPhone is not recognized and cannot be activated for service.  Please visit your nearest Apple Store for more information.  The closest Apple Store for me is over 110 miles away.
Connected replacement iPhone 4S to MacBook Pro.  In iTunes, I get the following message:  There is a problem with your iPhone.  We're sorry, the iPhone you connected is not recognized and cannot be activated for service.  We recommend you visit your nearest Apple Store for more information.  To find your nearest Apple Store, click here.
I'm still on the call with AT&T.  They transfer call to AppleCare tech support.  Verified IMEI no. and SIM card no. off of the SIM card tray.  Technician advises that the IMEI no. is not in his system.  We figured out that this IMEI no. did not match the number on my shipping box.  Verified the serial no. from the SIM card tray, technician never advised me whether that number was in his system, but it also did not match the serial no. shown on shipping box.  We tried the hard reset procedure twice, same results and messages.  We tried to get it to work with the old SIM card from my 1st iPhone 4S, same results and messages.  Technician brought AT&T guy into the phone call.  Verified and re-verified all of these nos. several times, from the iPhone 4S screen and from the bottom of the SIM card tray, although I had to find a magnifying glass to see the numbers clearly, they are very small.  The AT&T guy repeatedly related that there appeared to be no problems on his end.  I was getting a cellular signal with 3G, which apparently was able to attempt activation over cellular airwaves.  Also tried activation over my wi-fi network and through iTunes.  We were on hold for what seemed forever while technician tried to figure out the problem.
During the call, I received several calls from family wondering what in the he[ck] I was doing and why I wasn't home yet to grill steaks!  This procedure should not have taken longer than 10-15 minutes, but it ended up lasting 3 hours and 10 minutes.  The call ended when I got another call from home and I forgot to hit the HOLD button for the call to AT&T/AppleCare tech when I answered the other line.  I opted to go home.  Steaks are still marinating, we ate McDonalds.  Had an e-mail from the technician, left him a voice mail, I think he went home.
Later this evening, logged onto my Apple account which showed my registered products by serial no.  They have listed my initial iPhone 4S which I sent in.  They also have listed another iPhone 4S with the serial no. shown on the shipping box, which is inconsistent with the serial no. shown on the bottom of the SIM card tray of the replacement iPhone 4S.  I initially tried to create a Support Case No. online using the serial no. from the iPhone, not the box.  Was quickly given message that that serial no. was not valid.
So, I find myself again with an inoperable iPhone 4S on a weekend and the only option to get my old iPhone 3GS activated again is to drive 40 miles to the AT&T store to get another SIM card.  With no prospects for getting an operable iPhone 4S any time soon, the nightmare continues.
I have been a dedicated user of Apple computers and products (iPods, iPhone, iPads et al as they came out) for over 20 years.  Never have I experienced a nightmare of this magnitude until now.  Up until today, I would never have considered the thought of being on the negative side of Apple's top-rated customer satisfaction.
One can only hope that someone in AppleCare Tech Support with the authority to resolve such problems reads these boards AND is willing to look into this without delay (like before our steak dinner Saturday evening).  Are you listening (reading)???

Answer 1

NIGHTMARE Finally Ends, after nearly two weeks.
After trying for over a week trying to get my replacement iPhone 4S to activate, I ended up driving 110+ miles to an Apple Store to get a second replacement, which had been specially shipped there for me.  Popped in the SIM card, went through the setup and I finally have an iPhone 4S that works, at least for the time being.
Advice to others who find themselves in this situation:
     1)     If you get these messages (see original post), the phone is bad.  Demand a replacement.
     2)     If the AppleCare tech advises that the Apple Agreement Administration team is investigating, you'll be waiting for a week or more for them to complete it.  Demand a replacement immediately, don't let them put you off indefinitely.
After the initial phone call documented in my original post, I was in daily contact, phone & e-mail, with the AppleCare tech trying to figure out the problem, and we tried everything, from forced restore's to switching SIM cards, conferencing w/ AT&T, etc.  It seems that this was a case of first impression to Apple, but if it wasn't, then the problem is not well documented or known by those who should know, and for that, the blame should be on Apple, not the AppleCare tech who worked tirelessly trying to figure out a solution--I'd send him a case of beer if I knew where to send it.