Identity Theft: Identity Theft Laws

Hi,
I really need advise. My husband and I have been seperated for 2 years. He lives in Florida and I live in California. We have individual checking accounts. Recently I realized that the medical office that be both go to ( in California) has been using my debit card in my file for his telephone conferences and medications. They have debited approx. $10,000.00 out of my personal checking account without my permission. When I telephoned to tell them that there had been a mistake made and that they need to credit my account and debit my husbands account for his meds. and services they were very rude and refused to do this. They claim that since we are still married that I am liable for his medical bills. Is this legal? How can he have money debited out of my individual checking account without my authorization? We don't even go to the same doctor in this huge medical office. How can the doctors office refuse to re-emburse me when these are not my bills? How is this legal? I went to my bank branch today and they told me that there is nothing that they can do about this? Are they telling me the truth? I don't where to go or who to call for help.