IPhone: erase content and settings what would happen?

Okay so my phone company wants the iphone back even thou it's broken. So I deleted everything but if I click the erase content and setting will everything from the iphone will get deleted! I can't have anything on it or else I pay for having info on the iPhone.

The "Erase Content and Settings" feature is a factory reset. All of the information on the phone will be deleted and once the phone is powered on again it will present the Setup Assistant. (The very first thing that comes one when you power on a new-iPhone)

Thats what you want to do -> http://www.justtext.com/messageboards/20140127081812.html

Yes, it will erase everything from your phone. All your settings will be back to default, and your apps will be gone except the stock ones like weather, calendar… So after clicking that button, there should be nothing left and you can give it back to your company.