Internet Data

Would like to know why such the fluctuation with data information.  My son and I have been really trying to understand where the information is coming from. My "Other" data went from 8% last statement to almost 30% this statement.  Please tell me where this other data is coming from because we are really starting to question if this information is legit.  If this data is questionable and you can't put it in a category then is it really data???  I know they are in process of configuring the data information but honestly it's looking really dishonest. We have been calculating everything we do.  Also apparently we went over 1 GB over my account allowance last statement and was charged for 10 GB., which is fine but I really think unused extra blocks purchased should roll over to my next statement.  Just really frustrated!