Poor customer service

I have had my ADSL line for about 2 years now and when I originally got it installed I was told that I could go up to 10mb line. In the past a 4mb line has worked just fine but a couple of months ago I decided to upgrade the speed of my line only to be told by Telkom that 4mb line is the maximum. No reason or explanation given passed on from call agent to call agent and I still don't know why I was told I could have 10mb and now only 4mb available. I have now decided to move both my ADSL line and data to Afrihost and I sent cancellation documents through to Telkom on 25.01.2016 to cancel my ADSL line rental. I have called during the month to check that the line has been cancelled as I know their service is bad. Everytime I have called I am told it still isnt been cancelled and I must resend documents. I have sent documentation 3 or 4 times now. I am suppose to be moving over to new service provider today only to find out Telkom still hasn't cancelled my ADSL line. After giving them well over a months notice. When i call the call centre and after being passed from 1 call agent to another, I am told that the agent will email the cancellations department and they will call me back.