Telkom incompetence

In August 2018 I discovered that Telkom have billed me for 2 lines, instead of one, from August 2017. I logged a dispute in August 2018. In November 2018, they credited me for 3 months (instead of a year and 3 months). The agent that logged the dispute, incorrectly indicated that the double billing was from August 2018, instead of August 2017. I therefore logged another dispute on 14 December 2018. I have escaled the issue 3 times already, with absolutely no feedback or response from Telkom to date. As a result, my service have been suspended, even though there is a dispute on the line.