Vodacom

I had an account with Vodacom around 2011. It a two year contract and I was not aware that in expiry I need to cancel the contract. Vodacom continue to debit my account but it was more than the contract. I went to Vodacom offices only to be told that I upgraded my contract. I was surprised by this and I was requested to send some documents which I did. I was told that they will investigate and to date I have not heard anything from Vodacom. I noted that my credit profile reflects that I owe Vodacom and this has now negative effect on my profile. I want to know how far is Vodacom with their investigations and that they need to update my profile