Capitec says they send the debicheck to the client? I would not have authorized these amounts , where is their mandate proving I agreed to this amounts

DMC debit 300pm since last year, this month there was a debit of 2700.00 and 2449.00 by DMC Debicheck,I went into Capitec promenade on Saturday and spoke to the consultant as I wanted to know where the bank mandate is that i agreed to , why would i agree to deduct over 5000.00 when I 'm the breadwinner, she said i had to give the bank authorization and basically told me that a lot of clients lie by saying they did not agree , I did not agree via banking app, sms or whatever means , in the last few months , she reversed the money for me , but told me that she will only be able to do it this month and next month they will most likely deduct double and will block her to reverse, i understand that Debi check is put in place to stop ***** and unauthorized debits, but I did not agree or received calls or notifications from Dmc or Capitec within the past few months with regards to agreeing to debit these amounts from my account, i will today call Dmc and demand them to stop these unauthorized debits and will close my Capitec account . I am still a consumer and still have rights and does not like to be called a **** when I know I cannot afford these amounts