Forced to pay for \grace"days"""

So for the past few months Dstv has been asking us to pay twice a month. We asked why and they rep**** because we did not pay on our date we received grace days that we now had to pay for. I checked the terms and conditions and there is no mention of these grace days forced upon us. So in an effort to avoid grace days this month I asked them to disconnect my service for the remaining days before my payment date and they said they cannot do that, you can only disconnect a month in advance. Please sort your mess out, you cannot make us pay R699 twice a month