If somebody copy your whole website and name it with any other domain and address or contacts, what should we do? How and where should we complain about this?
First point would be their web host - gather evidence to prove they copied you and not the other way round. Depending on how long your site has been online for you may be able to use something like waybackwhen in order to validate your claim. That's the cheapest and easiest place to start, before moving on to lawyers and cease and desist notices. A polite email to the website admin might also be worth a shot.
i have 7 years old domain and website is popular. I have sent 3 emails to the admin but i got no any response from there. His domain is new. How can i complain it to Google? because i saw that website into Google search results.
See if this link helps you out: https://support.google.com/legal/troubleshooter/1114905?hl=en Sample DMCA Takedown letter: http://www.ipwatchdog.com/2009/07/06/sample-dmca-take-down-letter/id=4501/
DMCA may get that copycat site taken down in a hurry, or at least buried in the SERPS. Google doesn't take kindly to such things. I don't know about approaching the hosting company but it sounds like a good idea to me.
We as a hosting company take such claims seriously. But we do request that an effort to contact the web site owner be made first. If that fails then we will get involved and contact the web site owner ourselves and then if still now response we will suspend the site.