Contract still not cancelled at 10-14 days

I was called by someone saying they are with MTN. They said the data would be added to my current contract. They sent me a sim card that I immediately took back to MTN on 10 June and sent CCI-SA an email telling them to cancel. Lindelwa Ntuli send me an email saying it will be cancelled within 10-14 days. I spoke to Lindelwa again on 9 July asking why they charged me for June and she said there is a backlog with cancellations. I asked to speak to a manager and she said all the managers are in training. She also said Sam Perumal (A manager) will call me back. I am still waiting. I have still not heard from them and MTN is not helping me cancel this.