MTN **************** for data usage

My account is ussualy in the region of R900 p/month. The last 2 months my account was R1,800 p/m. I looked at my statement and saw it was mostly due to data usage. Now I dont have any apps running or updating I just use yahoo mail whatsup en internet to read news etc. How can this be?I tried calling MTN`s useless call centre and as expected they werent able to tell me on what my data was spend.So MTN I want to see exactly which websites was accessed. I further think you should be absolutely ashamed of the rates you are charging your customers. I am cancelling my contract and switching to Cell C feel the hard way where your pockets will be affected I am not entertaining a single rand to you anymore.Have been a customer for over 18 years good bye your service sucks big time