Bouncing debit otder

I have a sim data contracts with Telkom, for the past 5 months there were debiting my account on the last day of the month but to my surprise this month they attempted to debit my account on the 22th of October and there was no money in my account. My problem now is that I have to pay the bank R110 bouncing debit order fee.

I want Telkom to tell me who gave them an authority to debit my account on 22th and they must pay the bouncing debit to the bank because I never agreed with them to debit my account on the 22th. My account number is: *** and names MA Motla.

Thank you.

Kind Regards, Abel