My account is debited and I have not signed any contract and approve any debits from my account. 3 debits within 3 days

I have no contract, nor did I apply for any new contracts, and 3 debit orders came off my account iwitun 3 days. It was around R40, R50, and this morning R120.How is this possible , how did they get my information and my banking details. ***** and *****ing is a ******** offense. I contacted the ***** department, the lady cannot assist me. Said I have to mail the ***** department, no one contacted me directly from the ***** department.. I'm going to the police station and making a case against vodacom for taking money out of my account without getting my approval. . Can a head of sales department at Vodacom contact me and explain how this has happen. And to cancel my details from the system and to ensure that it does not happen again. Thank you