UNAUTHORISED DEBITS

On the 13 August I received an sms indicating that an amount over R2000.00 had been debited off my bank account with a Telkom reference. When I called the bank to find out who is debiting my account I was given a number of *** belonging to Nudebt to call and query with them. when I called today, I spoke to 6 people and each time I explained my story I was told that they could not pick anything on the system or that they don't deal with debit orders with a Telkom reference. What is shocking is what gives them to debit my account without communicating with me and without my approval. How can my account get debited and then when I call to query nobody knows what my query is about better yet no one is willing to help. As much as this a collections agent of which I don't even know who and why they are collecting on my account however rules needs to be followed. You cannot simply debit some ones bank account without their approval or even as so much calling them.