Discovery Commercial Insurance has disappeared and don't care.

I am trying to get some info on a Discovery Commercial Insurance policy/client. My email was returned saying they closed on 31 August. The phone number is out of service and no one at Discovery Insure has any idea where to find any info. How do you go about finding info of an old policy? This is very important information and it is required by law to keep this. Even the client doesn't know anything about it. Terrible service and lack of interest by Discovery.