iPhone 4S Recall?

I have one iPhone 4S (16GB) carrier locked and since the day one it's giving me a lot of problems.

First it was some random reboots, and a lot of kernel.plist on system diagnostics. I tried everything to fixed, with all Apple support and my carrier.

They said to restore my iPhone and don't use any iCloud backup and the problem kept, and after many restores, (and visiting my carrier to fix this problem, and what they did was only a restore and said: "problem fixed") but after a few days the kernel.plist keep appearing. And I didn't even noticed the reboots because it was, almost the time, when the phone was on stand-by mode.

So, after making a lot of tests what I did was deleting ALL THE iCLOUD BACKUPS and, once again, restore my device as a new one. And so far, everything is fixed and working great. Not a single kernel.plist on system diagnostics. ( 4 days using normally so far ) but TODAY other problem appear.

My wife tried to contact me and she couldn't because my iPhone has no network at all, only show the network name!

I disabled the 3G, DATA, Reboot the Phone, Search network manually, Disabled the SIM PIN, I did almost everything that I read here on Apple forums and my iPhone doesn't show any network bar so I tested that SIM card in another phone and it's working perfectly.

I did ANOTHER FULL RESTORE and AGAIN, no NETWORK! Seriously, this is starting to be VERY ANNOYING and my carrier says that there's nothing wrong with my iPhone because everytime they restore my Phone, all the problems disappear, but only for a few days!

Since I searched on the web for more details about this issue, all I see is A LOT OF PEOPLE having the SAME PROBLEM and 99% of the time it's on the iPhone 4S!

Im using the latest firmware (iOS 6.0.1) and now I don't know if this is a Software issue or a HARDWARE issue. Apple, as always, don't give us a "light" from what this could be... neither a FIX. And from what I saw, even when some people get a new iPhone, the same problem appear, so from what I think, seems to be a software issue!

Seriously, Im really tired of this, iPhone is known to be one of the best smartphones out there and it's expensive! I, like almost every user expect the best from Apple and Im a little bit concerned about this because my wife is pregnant and I can't trust my iPhone now... because if she has some emengency and need to call me I'm afraid that my iPhone can't be working!

Now I have my iPhone side by side to a old phone where my SIM CARD is working, to receive all the calls! It's totally a shame, seriously.

My carrier just don't give a S... about it (it's TMN from Portugal by the way) and Apple just ask me to do this and that and none of them fix my problem.

And by the way, If my iPhone will need to be replaced, I want a BRAND NEW PHONE, not a refurbished one like they did when I had one problem with my iPhone 4... if I paid full price, I expect a brand new phone, working perfectly.