MTN deducting money without permission

MTN SA has for the last 3 months you wrongfully deducted money from my account for a service I never agreed upon or signed for, ive logged complaints in various branches and online - my debit orders defaulted due to your deduction of R3548 this month - This needs to be sorted out as soon as possible as this is theft. I will be taking this up with the ombudsman and the National consumer commission. Every month I'm paying R80 to reverse your fault. The reference nr for this case is *** - Sort this out please.