Over charged or contract package.

I took a contract that is suppose to be R 150 a month only , some how a data bundle was activated to recur monthly , I did not activate it , now I tried numerous times to cancel the subscription for the data bundle on the web site , but no success . The web page is also not working correctly , when ever I log in and try to do certain things , a message pops up explaining that technical difficulties is being experienced and that technicians is working on it . I am paying for something I did not request or activated .