Q: Data plan has sky rocketed!

I have an iphone 5 and upgraded to iOS7.  Since doing so,  my data plan has sky rocketed.  I turn off apps,  and have wi-fi turned on when i'm at home.  Since the upgrade my data has more than doubled.  Is there a fix,  or at least a suggestion?  Also, the battery life is horrible since this upgrade too.  Is there such a thing as an undo?   Ugh!!