Data usage escalating !

I have a 3gig contract with vodacom second time around! Since June all off the sudden my 3 gigs are depleted around the 22 of the month. I called to submit a query on which they rep**** that is how much i use. This month is an all new low it is the 9th and my 3 gig is depleted! Im also running a cell c sim the vodacom is wifi, now when i activate the cell c 500 mb lasts me a month, but 3 gig last me 8 days, this is impossible? I only use the data for fb and email and one online game. This is the worst customer service ever. <br> Vodacom also removed the balance cheking facility that they had on the wifi interface, is this a coincidence i dont think so they are steling people's money!