Telkom continue billing despite cancelling account

I had an ADSL line with Telkom which was not on contract and then was offered a great LTE promotion by Mobile Talk operating on behalf of Telkom Mobile. I then cancelled my ADSL account as I didn't need two home internet accounts. I delayed the delivery of the LTE router as to avoid being billed twice in a month until the ADSL line was cancelled. I was assured the account was cancelled and took delivery of the LTE deal. I have since then continued receiving bills for the cancelled ADSL line and received an sms today threatening legal issues if I don't settle the outstanding balance which should be nil. I contacted Telkom and was asked to email a [Email Removed] who would resolve the issue. I have since heard nothing other than threatening texts of outstanding amounts. I have followed up several times with [Email Removed] and received no reply. The only correspondence I receive from Telkom is a monthly bill and sms for outstanding amounts which I should not be receiving.