any1 know how 2 set up 3g for maxis prepaid??

i've send the msg to maxis and it replies says that my phone are already activate, but when i turn on 3g got no 3g logo and can't connect to internet as well

so i need to set up anything in my phone??
PS: i've set the cellular data apn: unet, username: maxis and password:wap , anything i left out??

thanks in advanced.