Wrongfully charged and account debited without authorisation.

Cell phone service provider has messed up somewhere and is now debiting my account for about R11000 over a R289 per month contract. it has been 5 months and I have to go to the bank every month to reverse this payment. The value was supposed to be credited to me and the branch was supposed to sort out with the head office. phoned today and it is still not sorted.

I am still awaiting for resolutionz