If you want to deny access to their web site for a specific IP, do the following:
1. Do you have the IP address or hostname for the person giving the problem. If yes, then proceed to Step 2. If not, review your
/www/logs/access_log via the cpanel or from FTP.
2. Download access.conf in ascii mode.
3. In access.conf, add the following:
<Directory /www/htdocs>
deny from thesite.com
</Directory>
4. Save the file.
5. Upload the file in ASCII mode back to the /www/conf directory.
This will ensure people viewing your site from thesite.com will get a "Forbidden" error. They will not be able to view or navigate your website.