ulocked iphone 3gs on bell HELP :)

[madyicstik]

hello i recently bought an unlocked iphone 3gs 32 gb and im currently with bell mobility with a blackberry bold 9700 ia have 2gb of data on it but when i put the sim in the iphone the calling and texting work but wheni tried the safari to surf, the phone says im not subscribed to mobile internet(or something like that) i tried the step in bell's website about setting up the vpn (im not allowed to post links) but it still gives me the same error

can anyone help me? im a new iphone user.