Internet for Blackberry Storm with PAYG?

[Janey]

Hi
I was just wondering how internet is set up on a Pay As You Go phone.
I've unlocked it to o2 and whenever I try and connect, the message "Unable to connect to the Internet, please try again later." comes up.

Please can anyone help? I have a feeling i'm being stupid and the answer is right in my face...but yea...any help would be great

Thanks