Vodacom robbing me blind

<p>I've been on my current contract for almost 2 years, up until November 2016 my bill was roughly R1500 as of December 2016 my cell phone bill has been no less than R4300 which I can't understand as my itemised billing claims it's my data which is impossible as I'm constantly on WiFi and even if I wasn't it's not like I'm anymore on my phone than I was in November and for my bill to go up by rough R3000 is crazy, and after December when my bill was R4559 I was extra careful on my phone and yet my bill hasn't dropped, I watch my data and it's impossible for my bill to be that high, vodacom can't seem to give me answers to this, they keep saying it's data when Im not stupid nd know I'm always on wifi, they robbing me blind and I will leave Vodacom when my contract comes to a end unless this is sorted and I am reimbursed for their faults even though in the past I was paying for data that I had added to my contract and yet was never given to me, and that was never sorted either. The past 2 years Vodacom have made a joke of me by *****ing my money</p>