Unauthorised debit order taken off my bank account

I noticed an amount of R299 taken off my account and the bank put me onto Digicash on ***. The reference number was JBDMarket/4ZHZA. After having to wait 35 minutes in a queue, I was put through to an operator who could only tell me that the debit was requested by JBDMarket (whom I have never heard of) - she would not give me any contact details or any other information unless I gave her my banking details !!!!! I refused to make matters worse by giving this information out. <br> How does one go about finding out who requested the debit, how they got my bank account details, who have them authority ?? This is theft !