Indeed, the best thing to do is to give them the whois records.

Also you can communicate the link of our ANN on Bitcointalk: https://bitcointalk.org/index.php?topic=577207
There is also the ANN on Altcoinstalks: https://www.altcoinstalks.com/index.php?topic=312970.0

We have sent the complaint to the corresponding provider and are verifying the registrants details.

Again, due to the limited technical sphere in which Tucows operates, we do not believe that we are the correct party to contact regarding this matter.  In this instance, we suggest that you contact the party operating the website or the party hosting the website to have this matter properly resolved. A "ping" of the website you indicated often reveals the IP address of the party which probably hosts this website.  A "ping" of the website you indicated often reveals the IP address of the party which probably hosts this website. You may then use https://hostingchecker.com, https://search.arin.net/ or another similar tool to identify this party.