From Consumer Wiki
Businesses that sell but do not install carpet must have a local city or county business license. Installers must be licensed by the California Department of Consumer Affairs, Contractors State Licensing Board (CSLB). These businesses must have a local city or county business license.
Contractors State Licensing Board
9821 Business Park Drive
Sacramento, CA 95827
The Better Business Bureau (BBB) records complaints for manufacturers and carpet sales people.