No authorisation given on an upgrade

Disgusting service from Cell C, I received an sms that one of my accounts has been upgraded, this was a surprise to me as I did not do an upgrade I called customer care, they put through to upgrades, I asked them to stop the upgrade but I was told that I must go back to customer care. They were not helpful. I then called the ***** line and was told that must get an affidavit, and send them an e mail. When I asked them to tell me how was the upgrade done, I was told via a call. I asked who was the agent, they could not answer. I requested the call recording, that could not be provided. Also strange how a call was made to a data only Sim! So basically ***** is happening within their business but it becomes my fault and my problem