Hi jhcl,
You are NOT crazy, but this situation could drive anyone crazy. I am so sorry you are having to go through this.
You mentioned that your iPhone 4S is slightly under 3 months old. That is significant as there is a free 90 day support service that Apple provides. I have used it in the past for other products and have found the service courteous and very helpful. I should add that on occasion the initial contact person you speak with may not be able to handle your issue...either because of its technical difficulties or because the solution requires approval from someone higher up the ladder. I have never had to ask for this "bigger dog." The initial contact person always realized he/she couldn't solve the problem and solicited the help of a senior person. However, if you don't get satisfaction from the person you talk to, then please ask to speak to their supervisor. Also, I wouldn't call on a vacation day or even a weekend if possible. My experience has been that the expertise of the phone help on those days (vacations especially) is not up Apple's normal standards.
Here is the link:
http://www.apple.com/support/iphone/contact
It will ask you to input the serial number of your phone. But, then you should be able to make the call under the 90 day free policy. I think the link also has the number you can call straight away. They will probably ask you for the serial number first to verify the 90 or less issue. It's 6 of one, half dozen of another.
I hope you come out of this with a new phone being mailed to you as you have already tried all the suggestions from this forum...most importantly getting a new 128k SIM card (is was 128k right?). My personal experience with Apple products that fail to work correctly after I have tried EVERYTHING Apple has suggested to rectify a situation and still nothing works is that the "90 day support line" is your best option to get a replacement for your product.
I am assuming that you do not have access to an Apple Store and a Genius Bar. This would also be another very viable option for you. But, I would take advantage of your 90 days of free phone service if it were me.
Last thing...when I've called this 90 day service before I have also had my computer next to m, online. Why? Because sometimes giving them, or sending them via e-mail while on the phone, the link to these discussions can help the Apple Support person realize the extent of the problem. I suspect that most Apple personal do not read these forums on their free time for pleasure!
I believe this link will get someone straight to this particular GINORMOUS discussion thread:
https://discussions.apple.com/thread/3390945?start=1200&tstart=0
Let us know how things turn out.
Best, Mr. Luigi