I've been having issues with my phone for forever. I have the common phone touchscreen won't respond in certain spots, screen randomly goes to different apps on it's own, calls people, freezes all the time and all that jazz. I'll admit to having dropped it a couple of times, but nothing major...it's not totally jacked. And my previous Shift was doing the same thing and I didn't drop that one. My main problem is now that I can't access the internet or any of my apps that require internet service unless my phone is in 4G. I have the wifi connected, and it says to check my settings all the time. The 3G icon at the top of the screen is nowhere to be found. Also, I only get that message for certain apps. I've found one app that the 3G doesn't need to be on the screen for and it works just fine. I don't know what to do about it. I was just going to tough it out until January when I'm available for my upgrade because there are some apps that I will lose all my progress on if I get a new phone.
I am sorry that you are having problems with your device? Have you tried turning your phone off and remove the battery for a full minute then power back on? Another thing you may want to try is to go to to your settings on phone, go to menu, wireless and networks and make sure mobile network is checked. if it is, maybe you can toggle it off and back on and see if that helps out with your 3G. If that continues, I would suggest you take to a service and repair store and have your phone tested.