Two long phone calls later with Multichoice with no hope of a resolution yet

I prepaid for an annual DSTV subscription in March this year. Up until June this year, my DSTV invoices all reflect that I am up to date with payment. But my July 2018 invoice contains a myriad incomprehensible items, the bottom line being that according to Multichoice, I owe them R183.34 (which is not correct).

I have spoken to their customer service department twice. In both cases the representative acknowledged that this is mistake, and promised to rectify it. But this has not happened. According to their records, I still owe R183.34.

The second time I spoke to the customer service department, I asked for a reference number. I was told that this is only generated at the end of the call, and that the reference number will be sent to my cell number. This did not happen eiter.