Q: Iphone 4 - using lots of data - Please Help :)

Hi,

Hope somebody can help me! I recently got an iPhone 4, never used an iPhone before.  Its amazing except its going through tons of data!! I live in South Africa at the moment, so theres nothing like unlimited data, so really cant afford to keep having to upload more and more data.

I have turned the notifications off for all games, facebook, and mail.  Only notifications remaining are WhatsApp.  Please help!!!

Could it be a certain app??

Thanks so much!!!!!