******* with services

I took out a contract in February with cell c. I had no problems with my data coming through each month until October the 4Th when all my data disappeared and my mobile data being off. I thought it was something i did wrong so i went to store and i was told it my automatic updates that went off. The consultant advised what to do. He checked my setting him self and turned it off. November 3rd all my data disappeared again with my tablet and mobile data being off. I contacted customer services with a query they responded 2days later advising that everything is normal , i then asked them to email me the finding. I had to call back a few times for the email. I eventually got the email and i see is that my data being used when its wasnt even on or to sites i dont even know. Im very upset with this as why should i pay 4 something i never used and all im getting from cell c is that everything is fine ND normal on that side. I dont feel then need for this contract if the purpose was to have Internet access and now i have nothing. I DONT MIND PAYING FOR THIS BUT GIVE ME WHAT IM PAYING FOR.