DSTV (Multichoice) is *****ing My Money...........

I am at my witts end. I am locked in a 24 month contract with DSTV on DSTV Pricelock. Three months ago they deducted an extra R99 from R959 to R1058. Several phone calls later I am still not paid back as promised. I left it. Now three months later again they deduct R1078. I got sent from Pillar to post and still no joy. One agent told me she cant help me. The next said she will escalate this and when I asked for the number to phone myself she says there is no number. DSTV is *****ing my money and I can do nothing about this as I am locked in a contract. DSTV know this, as soon as my contract is done, I am done with you. Is there anybody that can advise me what to do, do I go open a ******** case or what stands me to do. Please help.