DSTV PRICELOCK IS ABUSING ME

I took black Friday deal of R499 in December 2019 with pricelock. But DStv debited me R897 in January 2020 and R649 in February 2020. I fought with them for the whole month of January 2020 and subsequently good refund of R300. 00, but again I'm stuck in the same situation in February 2020 whereby extract R150 is debited ********ly so since we have a 12 month contract for R499.. Why is it difficult to deduct the correct amount and leave me alone.