High data usage

My first post was removed. Isn't that odd... so, my issue is I have recieved texts/emails stating that I have used all of my data up for the month. This is the 7th of February and I have managed to use up all my data. How is this possible? Nothing has changed! I have not gone over any data in over a year (+) and all of sudden I've used it all. I am afraid my the end of the month my usage will triple! I have restarted my Modem, and haven't seen any changes. I know I am not the only one, so their has to be an explanation as to why all of sudden this is occurring.