Fido

Sometimes the stores run a plan that the customer service dont know about. My suggestion would be go back to the store and ask them about it. 

What kind of phone are you using? If it is a Iphone, check your wifi-assist. Which can be found under Settings>>Cellular>>wifi-assist(at the very bottom of the screen), make sure this is turned off(Greyed out). This can cause high bills with data use...