Telkom charges double for services

We were on the 10GB + 10GB Home LTE package (R399 p/m) when the new unlimited uncapped LTE package came out (R599 p/m). We called to get more information and they said we could migrate without a problem - the Home LTE will be cancelled as soon as the new package has been installed and is working fine. As soon as the new system had been installed and working properly we called them again to cancel the Home LTE package. They disabled the sim card and we thought that was the end of it until we received the statement at the end of September. We had to pay pro-rata from 22 Sep to the end of the month for the new system - no problem with that but instead of giving credit for the old package for that period it was never cancelled. We called the customer care centre on 2 October to report the problem and we were promised that it would be taken care of. Then we received another statement at the end of October and it still had not been cancelled. We called the centre again and this time we were told they had no record of a cancellation or any communication, we'll have to go and cancel it. This is unacceptable. They shouldn't promise just to sell more and then not take responsibility.