Telkom invoice for non-existing service

I decided to take the home LTE service from Telkom. The call operator I interacted with when taking out the LTE service advised that I cancel my existing ADSL line service, She advised that I complete the relevant cancellation form which I duly did and sent to ********** . They acknowledged my request on 27 July 2017.

Further to reviewing my latest statement I noticed that Telkom are still charging me for the ADSL line even though they acknowledged my cancellation request and I no longer use the line. I called the Telkom helpline on 28 September 2017 and spoke to Zinhle - she mentioned that it appears the request was not completed by their cancellations department and that she would send the acknowledgement email to them to expedite the refund. Zinhle also promised to provide me with some feedback. Well a considerable amount of time has since passed and Telkom have not issued a revised invoice and Zinhle has not bothered to get back to me. Very disappointing!