Cannot install google Sitemap in Rapid Blog (Name.Com)

Rapid Blog (name.com)
I had a blog with WP, recently, Name.com started hosting service for WP. So I moved to Rapid Blog.
my problem is I am not able to make a sitemap.xml

When I reported to Name.com (Rapad) they sent a mail to me I copying as it is below:
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Good to hear from you. You cannot CHMOD any files because you do not
have root access to the server with Rapid Blog. The only way you could
do this would be through WordPress.com. You should be able to install
a sitemap file for Google with no problem as long as you do not modify
the file. Please see this link:

http://www.arnebrachhold.de/projects/wordpress-plugins/google-xml-sitemaps-generator/

Regards,
Sky
Name.com
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I visited the link and downloaded the plug in called Google Sitemap Generator 3.1.2.zip and tried to install. first time the error was could not create sitemap.xml (write permission). later I started to get below given error. many time I contacted Rapid Blog. No reply, nothing. please someone help me. If I am not able submit my blog to Search Engines my many years of work is useless.

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Installer Error

Can’t create file ‘google-sitemap-generator/sitemap-core.php’ in ‘/ebs/accounts/b/www.burzar.com/wordpress/wp-content/plugins/’

View the full log
About to extract ‘/mnt/upload_tmp/phptgQO0I’.
Extracting files from /mnt/upload_tmp/phptgQO0I…
So far, the type is set to ‘plugin’.
Need to load PclZip.
gzopen() found, will use PclZip.
Starting extraction to folder ‘/ebs/accounts/b/www.xxxxxx.com/wordpress/wp-content/plugins/’.
Extracting google-sitemap-generator/sitemap-core.php
Can’t create file google-sitemap-generator/sitemap-core.php in /ebs/accounts/b/www.xxxxx.com/wordpress/wp-content/plugins/!
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At least someone tell me to whom I have to contact. WP? or Rapid Blog?