Fraud department of HSBC refused to talk to customer

PF in California says money disappeared from her/his bank account. “This company debited funds from my bank account. I have never done business with them, ever. I called them directly and was told that I could not talk to their fraud unit to complain….to determine the ISP of the computer that supposedly did this, etc. ….but because I did not have an account with them they refused to talk with me. How did they access and get money out of my account then?????? Is this their M/O, should I close my bank account? “