How to properly disable data roaming?

[beanex]

Hi All,

I don't think this have been asked before. Recently I got charged for 301KB data roaming in Canada. Even though it was pretty cheap ($0.002/KB), but I don't understand why. I didn't surf/email when I was there, and I am pretty sure my weather wasn't updated.

Possible application that accessed internet:
Outlook
SPB Weather

In my phone setting -> Services -> Roaming -> Data roam guard:
I have "uncheck" allow roaming
And I did "check" never ask

I thought every application that access data must go through this setting, correct? So why did I get charged data roaming?

My question is, how can I disable data roaming, or just disabled entire data connection?