Ridiculous data charges

Since I have recieved my Galaxy Note 4, I purchase an average of 6gb of data per month. This is ridiculous and unreasonable but have given up on contacting the call centre as nobody is able to resolve my issue since March 2015. I have taken my phone into a Vodacare store where a technician checked out my settings, swiched from us<br> ing lte to 3g yet I'm still faced with the same issue. Every time I call to address this issue,im refunded a small portion of the data which often finishes the same day and is completely pointless.<br> Yesterday 250mb lasted me no less than 1 hour which isn't realistic at all. Other than the fact that my phone only downloads with WiFi etc., my data usage on my phone indicates that I use much less than what im charged for. <br> I can't afford to be ********** more than what I have.<br> I would like a solution to my issue or cancel my contract. I'd also like a full refund of the data that I bought but have not used.