Billing *****

Vodacom contacted me to take out a new data contract. I agreed to the proposal. I then received another call a few days later to confirm , and suggested an additional add on to it. I refused the add on, as the amount did not fit into my budget. They still went along and billed me for everything. When I called the customer care centre, they twice cut the call after explaining my problem. I then send an email to which I have not received an acknowledement or reply.