I would try his home address in Costa Mesa.
The last place I see he had his commercial real estate license through is R & R Consultants & Investments in Orange County. The broker -- and his partner -- appears to be Larry Roybal.
If that doesn't work, there is always the Dept. of Real Estate for the State of CA. Something tells me they don't like seeing cases of R.E. fraud. His DRE license number is on the home page.
Roman Libonao currently resides at xxx xxxxxxxx Ave. Costa Mesa, CA 9262x. If you've had PO Box bounce-back or phone difficulties try writing this address instead.
We did a service call @ 12xxx xxxxxxxx Ave. # E Garden Grove CA , the invoice has been returned to us, numbers are disconnected, resent it to PO Box which was listed as forwarding address! Still no response, This is from 9/28/2011
Argh! Beware Please