Cancellation made impossible

I called the contact centre in December to advise them that I need my number converted to a prepaid as I don't want to renew the contract. I was advised that I need to send a cancellation in January when the contract ends. Can you imagine the surprise I got when i called the contact centre on the 27th January and was told that it takes 21 working days to cancel the contract. I called again today, 17 business days and was told there is no case on the system logged. I am worried i am going to have to wait 6months same as I have been waiting for the technicians to call me to set up voice mail. how hard can that be. Other networks have a self-service that enables that but it's impossible with Telkom Mobile. I am getting the same service as Home Affairs; are they getting training from the same place.