Why do i have to buy so much data

<p>For the last couple of months i had this mistory that my data is very high, last year i had a online store and used my phone much more then this year and came by with 1gig</p> <p>No for the last months 1gig is only holding for a week, i have to buy 2-3 gigs a month and i have wifi at home and at work, please explain to why this is happening because i see a lot of Vodacom users complaining about this, Also</p> <p>I took out a new contract in August and u are still putting charges on for 3g laptop installement R230 that was on my tablet why are u still charging me for this </p> <p>I paid this in Sep and Okt can i get a refund for this. </p>