I bought a LG phone from Wal-mart. I was given a Iphone 3gs 6.1.3 I put the sim in the Iphone and I get service for calling and text but no Internet unless I am near wifi I can connect to. I have an unlocked phone. I have been back and forth with Straight talk. I want internet!! When I go to setting, general, cellular, I can get to cellular data and can't go any farther. I have no APN to put in info to be on straight talk. When i go to about I am still on ATT 14.2???
http://www.unlockit.co.nz/unlockit/ You should also try the SEARCH feature here, you would find so many answers to this. I have answered this many times, Heres what you should try go to unlockit read how to get the Data working,if this doesnt work,remove unlockit , then Use the tethered jailbreak for IOS 6.1.3 and go to Cydia, and buy TETHERME this will give you Cellular Data Network where you could input APN setting's.
There are a few different settings depending on what SIM card you have,Pull sim out and write down numbers and search google,bing and you'll find which sim it is.Then try all the different settings one of them will work.
If you dont want to Jailbreak then BUY a T-Mobile sim and do sim swap, all of these are the most popular way to fix APN and MMS
With the info you have supplied it's hard to help, I'll have to Guess,,,maybe you put something wrong in the Cellular Data Network settings. So you J/Broke your phone installed TETHERME and what settings did you input???,, When you tried T-mobile sim swap, What did you input for setting's,and you haven't said What sim it is in your phone,AT&T,T-Mobile< Did you activate LG phone first,So it's hard to figure out.Do you have 3G enabled in settings,
In the beginning when people bought ST phones to use the sim there was only 3 phone's you could do that with,Nokia E71-E5-6790, sim numbers were TF64PSIMC4 these were unlocked sim's, what model LG phone did you. If you have a ATT sim I have found about 4-5 different settings,I would put the sim back in the LG and see if you get Internet,talk text and MMS working then give us some info on your ph. Lg and iphone,what settings you have tried more info more help
One more thing I thought of since it works on wifi. Does talk text MMS Internet work On Wifi only or does talk text mms work on 3 G and not Internet. We bought a E71 and it wouldn't work at all driving around but worked on wifi so it turns out Sim was bad. I'd like to know if it all works (talk text mms Internet ) in Lg