Pharmacy put medication under wrong patient's insurance?

My Mother dropped off a prescription to CVS to be filled. After my Mother picked up her prescription, a lady with a similar name came into the same CVS and dropped off her prescription to be filled (Methadone). CVS forgot to ask the lady for her DOB, address and insurance information. When the pharmacist went to process the medication and insurance information, they put it under my Mom's name, as the name was very simlar. Now, my Mother has a medication on her insurace record that she was never prescribed or given and my Mother's insurace was billed for the medication. What laws does this go against?