Dstv debiting for Netflix without authorization and incorrect amount.

How *********** can Multichoice be? They have debited me for a Netflix account, which I am subscribed to and pay at a different bank. Mind you, my Netflix subscription is for R99 a month, but Dstv went and debited me with R199. And when you call their line ***, you are told you will be refed as they don't have an explanation. How can you debit a person's account without their authorization?