DStv debits my bank account without permission

<p>There was a mix up between my dstv decoder and someone else's. Although I submitted bank statements to proof that my account was debited every month albeit for a different decoder, Multichoice still went ahead and debited R8400 from my bank account!!! I would like to know how they are able to transfer funds directly from my bank account to them without my knowledge or consent??!!! This is surely *******.</p>