Charged and being threatened with blacklisting for no service received from Telkom

I have been charged for 2 months of no ADSL service (April and May). When contacting Telkom, there automated voice prompts say that you will be credited the following month. This did not occur. As such I reversed one debut order. I have contacted Telkom 3 times to enquire about when the payment will be reversed for the other month. I have this month been debited R1150 (My normal fee is R604). I was told that some of this is for a failed debit order . Today the consultant told me that a manager would contact me today. When I asked what route I could follow if this did not occur, I was sarcastically told to phone again tomorrow and I was also not provided reference number.

I also keep getting messages being threatened that I will be blacklisted! This is ridiculous as they owe me money.