Being billed for a cancelled service

I had the telkom lte for my home use.I was running out of data,I changed to ADSL.I cancelled the lte when the ADSL was connected.That was in October 2017.Telkom has been billing me and debiting my account for the Lte.I pay for the ADSL separately.I have emailed the person who was handling the cancellation.She has not responded.I phoned the customer service billing department and spoke to another person.She asked me to forward the emails to her.I did that and have not heard from her.I've been into the telkom store several times and the consultant sent emails to the two people I communicated with.They have still not responded.I've had to go to my bank and stop Telkom debiting my account.The bank reversed some of the debits.Telkom owes me around R3000.This month Telkom debited my account with another amount and that debit went through.I had to go to the bank again and get them to stop the telkom debit again.Why is there no one who can resolve this?? I'm really frustrated with Telkom.I need someone to help me.I have the names of the people who I have emailed and I have all the emails sent to them.