Incorrect billing and agents not giving feedback

I have contract with MultiChoice and in May 2014 I called them to activate extra view for me. While speaking on the phone with a female agent on what to do then we got cut off towards the end of the call and when trying to call them back then the extra decoder was playing then i stop the call coz now it was playing. They are debiting my bank account on monthly basis as that is our agreement but now after 6 months i've noticed that MultiChoice was debiting more then the R75 charge for extra view and they were actualy taking R399.00 subscription for package that I did not have any clue about it so I called them for an explanation and spoe with Luewelen and he informed me that the package was activated on line but does not know who did it so i asked for an investigation to be done in which he promised it will be done and his superior will get back to me in 7 days which never happen. I called again and spoke with Phamela Mncube who also promised me a Supervisor will contact me within 24 hours and gave me a Ref no:*** and that too never happen. I want a call from their Supervisor and I want to know who activated the package on their side without my knowledge.