3G internet not working
I've had the iPhone 3GS for a year and not experienced any problems with it. But in the last few days, I've been unable to connect to the internet via 3G. It works perfectly fine via WiFi and I've tried the SIM in a different handset and it works fine, so that's not the problem.
Strangely, it does however work in certain instances, for example I can receive WhatsApp messages and some push notifications, but it will not load internet pages, Facebook, Twitter etc. I've also noticed that the battery is running down quicker than usual
I've tried resetting the network settings, along with resetting the phone on several occasions, neither of which seems to have helped.
iPhone 3GS (8GB), iOS 5.1