3G never worked on my iPhone 4s?

Someone please help me!

I had a contract with o2 for a blackberry my 3G worked fine but I decided I wanted an iPhone 4S so I ordered a micro sim on the same contract ad my 3G doesn't work? I've tried resetting my network setting it doesn't work!

Google it

Maybe the phone doesn't support the bandwidth frequency of your network provider.

I think it might be because you had a BlackBerry before. You might be using a different type of data plan. You need to phone O2.