Poor service

I have been using Vodacom since 2009 but never being disappointed like this. I opt to home internet contract this year and paying 449 for 600gig. Yesterday they decided to deactivate my sim card . I am nolonger enjoying their service hence i am paying every months. I have been buying datas since yesterday. To day i called consulted she is teling me that i failed some of security questions so they can not activate my sim card. I dont know which question I didn’t answer correctly . I believe that they might have my incorrect information and now i must suffer because of the agent who assisted me when joining. I called cancellation department to cancel my contract but i didn’t get hold of them and the lady who was was assisting me refused to transfer me . This is painful. As i am loosing money buying their data’s every day while on contract