not delivering on promise

I received a phone call from Vodacom in January 2015 informing me that I qualify for an upgrade as well as a top up of R99 on my existing contract. I was in fact interested as I wanted to increase my subscription amount at that stage. I was informed that a top up can be done on my existing cellphone number. When I received my new phone a few days later, I also found that there was a sim card with a new cellphone number. I tried contacting the person that phoned me initially on *** but could never get hold of him. I then left several message and a certain lady phoned me back that informed me that the top up could not be arranged on my existing number, and that is why they sent me a new number. As I was not interested in having another telephone number, I requested them to cancel the top up and I returned the phone. The phone was collected on 07/05 and I was informed that I will be refunded from end of January for the R99 that was deducted and the new contract will be stopped. None of that happened, I was not refunded and R99 still gets deducted from my account. I left several messages again, but no one seems to care enough to even phone me back.