unauthorised debiting of bank account

Who are Nudebt? I have not received any communication from them yet they debit my bank account unauthorised. On investigation, they are contracted by autopage who have mucked up my account and handed me over to nudebt management, wrongfully. My account seems to be rectified at autopage but still nudebt put through unauthorised debits on my bank account. When I called their customer service line they can't find any details pertaining to me. When is my account going to be credited? Can someone please tell me. Who gives you permission to debit my account when it suits you without any communication of any sorts?