Help needed - Network has just stopped working.

So my problems so as follows. In the morning I use my data, go on some website, then turn it off. Maybe 5-6 hrs later I decide to use it again, guess what I just doesnt work. It literally stops working by itself. I tried everything I can think of. Restting all setting, reset network settings, and I even did a full restore and updated to 3.1.3. Still doesnt work. I see the carrier logo, 3g logo, and full bar signal strenght. I cant make phone calls or surf the web using 3g. Im going to see my carrier tomorrow. What can I do now?

 

Ya I did. Its not due for another week. Now it seems to be working. This is ****ed. If it happens again in gonna take it to the store.