Bing listet Webseite trotz "Verbot"

Du könnest die IPs vom bing bot sperren oder denen einfach keinen Content ausliefern.
Siehe http://www.bing.com/toolbox/verify-bingbot

Da dürftest Du recht haben, aber schau mal was ich bei den bing webmaster tools gefunden habe:
http://www.bing.com/webmaster/help/block-urls-from-bing-264e560a

The best way to block URLs that are currently published on your site from showing up in the Bing search results is to add a NOINDEX meta-tag to the HTML header of the page. This tag tells Bing to never add the page to the index, and thus, to never show it in the search results. To be able to do so, Bingbot needs to be able to read this tag on the page, so although this might sound unintuitive, you should not disallow crawl of pages that have a NOINDEX tag in your robots.txt. Robots.txt governs what search engines can visit (that is, fetch from your server) not what they are allowed to add to the index. You can read How to Remove a Page from the Bing Index to learn the best ways to remove a page that already has been indexed from the Bing index.

WHEN TIME IS AN ISSUE

However, sometimes you need to block a page on your site quickly – that is before you can fix a page’s meta data on the page or completely take a page that you no longer want searchers to see down from your site. This is where the Block URLs feature — which you can find in the Configure My Site Section — can help. The Block URLs feature allows you to temporarily block page and directory URLs as well as cached pages from showing up in the Bing Search result. This is useful as it buys you time to make the necessary changes to a page’s metadata or take a page down.
USING THE BLOCK URLS FEATURE

Here's how the Block URLs feature works:

Select the type of URL you wish to block. You can choose either Directory to block an entire directory and it's contents from showing up in the search results, or Page to block a single URL
Enter the full URL you wish to block
Now click either Block URL and Cache to prevent URL and the cached pages from showing up in search, or click Block Cache, to only block the cached page from showing up.
The URL now is added to the list of URLs you have blocked for a period of 90 days.
If you still need to manually block a URL or Cache after 90 days, you will need to extend the block using the Extend button