Unauthorised debit for second month in a row

I am here yet again second month in a row where on air is robbing me of R199 again They have not stopped this unauthorised debit and still not given me my last refund what must I do to stop this I really need a person of authority to deal this matter and they must not tell me lies about 7 to 14 working days as they have not even stopped the debits on their side so how can I trust maybe I must take this to ombudsman I never even agreed to debit I returned their decoder months ago I paid the fee they wanted yet they taking my money and they have a nerve to debit me and theylir company still tries to sell new one daily to me what nonsense is this