My 3G won't work on iPhone 4s ios7?

My phone will not connect to 3G. It comes up with 3G at the top left of my phone but I can't connect to the internet at all. I have tried resetting my network settings but nothing works, I with vodoafone. I really need to sort this out, would changing my sim or changing my mobile network to EE or something help?
If anyone knows please help because I really need to fix it, thanks

If you're using prepaid, you've probably used all your data up. All you gotta do is recharge and it should start working again. If not call Vodafone support.