Money been ********ly deducted from bank account

I noticed an amount of R39.34 been deducted from my bank statement. I obtained a telephone no ********** from mercantil bank and spoke to a lady by the name of Susan who informed me that a telly marketing agent phoned me and I agreed to accept the said amount to be deducted from the bank. I do not recall any such phone call. It must have been written into contract which I had with altech for a cell phone which ended over two years ago. I told Susan I wanted the company to refund me my money as I had not agreed to This contract. She said she would not be able to do so and would I like to cancel my contract. I received notification to say it was cancelled. I feel very strongly about the whole thing as I feel that these deductions were ******** and I would like my money to be referred to me. My ref no is 105582. Thank you. Jenny