@Luddite I checked that thread before starting this one.
I honestly could live without a cell phone but the world won't let me 🙂
Don't mind m28 as you can get data to work on i3gs! Just requires using an APN editing website. The only caveat is that it will make MMS unusable.
@DK, I remember reading that if iPhone is not using latest is or firmware thing, data won't function, as I remember the multiple posts from ages past on that. Also, iPhone 3 and 4 to a degree are kinda ol and not too much support as opposed to iPhone 5 and now 6
You could try installing the applicable APN settings from unlockit.co.nz with safari on your iphone viaa wifi hotspot or other wifi connection.
I just switched my iphone 5s runninng IOS 7 and could not manually enter proper network settings to get public mobile network to work. I had to connect to a wifi, then visit unlockit.co.nz to install the APN provisions for my phone. It's free btw.
I think the maximum supported ios for the 3gs is ios 6.16
@DanZap while it's nice of you to weigh in with some helpful suggestions here, please note that you've replied to a thread that's been dormant for just over 3 years, last active in Dec 2015. I don't think anyone on this thread is still waiting for help, I'm pretty sure they've got it sorted out by now, or moved on to other things.