bad service from vodacom

I'm am very disappointed at vodacom once again. A few years ago a consultant had called me offering an airtime package of R50 a month, the consultant there after asked me how did the deal sound, i said i was a good deal however i never agreed to wanting. They asked for banking details which i then asked them to call me some other time. a month later i received airtime assuming someone had sent it to me. A while later i tried loading airtime which didnt work and waz informed that i was on a contract. I didn't agree or authorise this!! I lodged a complaint and had a call to say everything was sorted. Now im receiving calls that i owe R1600 for the contract and life insrance which again i never authorised. You guys record conversations please go back and sort it now!!!!! I will pay for the airtime that i used thats all. Pathetic network!