You may verify your site on Google Webmaster using the Meta tag option. To do this, Select the option "Add a meta tag to your site's home page" and then copy the meta tag supplied for your website/store. You then need to paste this tag to the "Head code" field below the Template section in the Store Configuration page.
Please refer to the Link hidden: Login to view for more information. Let us know immediately if you are still having any issues so we can inform our senior staff on your behalf!
Hope this helps :)