I have to pay for an error made by the company

2019 April I saw a price lock deal and I decided to take that deal up before taking the price lock I was using my HD and it was a compact plus so as soon as I got my explora I went to my maponya mall so cancel the HD completely since I will be using the explora the agreed Price was R649 for 12 months since it was a price lock then I have been paying that money ever since then November in the 27th I paid as normal then on the 6th of December my package was suspended I called to find out what was the problem since I made my payment as normal I was told I need to pay R1200 not R650 I asked for the break down of the R1200 I was told that my HD is active plus the Explora I asked the lady who assisted me how so cause I cancel the HD in 2019 I don’t even have the device anymore then I was told it was an error and my package was active fine on the 21st of December I made another payment which was January then on the 3rd I wake up same thing I called again I was told unfortunately I have to paid for that HD that’s why my package is suspended the payment I made on the 21st was part of my December billing I told the lady I can’t pay for an error that was made by the company I paid the agreed amount and m expecting my package to be active I was told they will fix it I must give them time since last week until today I have been calling trying to fix this but m made a fool on every call I made so m tired of fight as if m not paying so I want to cancel my subscription completely and I want nothing to do with DStv and I want my money back please fix this before I take matters into my own hands I don’t want any explanation I just my money back and cancel me