apache virtual hosts not working for new domain

I probably did some really trivial mistake but somehow I can't figure out where is the problem.

until now I had my debian vps running with few virtual hosts using one domain and several subdomains.

now I have new domain pointing to my vps and I would like to create same subdomains as I had with my old one.

/var/apache2/sites-available/mysql.old.com:

<VirtualHost *:80>
        ServerAdmin ****
        ServerName mysql.old.com
        DocumentRoot /usr/share/phpmyadmin
</VirtualHost>

/var/apache2/sites-available/mysql.new.com:

<VirtualHost *:80>
        ServerAdmin ****
        ServerName mysql.new.com
        DocumentRoot /usr/share/phpmyadmin
        ErrorLog /var/log/apache2/mysql_error.log
        CustomLog /var/log/apache2/mysql_access.log combined

</VirtualHost>

they are same, yet the new one I added today doesn't seems to work. I have used a2ensite on it and simlinks are created in sites-enabled, I have reloaded apache2 service.

logs are created in /var/log/apache2 but they are empty. also error.log and other_vhosts_access.log are empty.

are there any other logs I'm not aware of? which files should I delete to return to default state so I can start again from scratch?