How to disable internet on the samsung impression?

I have the samsung impression and Its easy to accidentally go on the internet. I don't want the internet and I get charged for when i accidentally go on it. Is there any way I can disable the internet so i won't get charged?How to disable internet on the samsung impression?Call AT%26amp;T and tell them to block the internet on your simcard. If you ever get a data plan later on you can have them unblock it.