Terrible service from Telkom

So I cancelled my landline on the 26th July 2018. MY account was debited on 31 July. I received an email in November stating that my cancellation has been done and has been backdated the 26th July. I never received a statement again. I thought that everything was perfect and done.I received a lawyers letter acting on behalf of Telkom the other day. I decided to check my credit record with Transunion to find that I have a poor credit record because according to telkom I am seven months behind in payment. How can I receive a letter stating that my cancellation has been done and that my account has been closed, and not receive another statement. I have tried to get answers but no one can assist. I am looking for an explanation. I find the service from Telkom to be revolting.