Unauthorised tracking on my bank account

My nedbank account was handed over to them and I settled it last month and when made the settlement I informed them that they were taking money from my bank account and they told me they did not have a debit order on it yet money went off my bank account this morning. I want my money back I do not have a debt with you or anyone for that matter so please resolve this mess immediately and stop tracking my bank account using different reference numbers.