Q: The podcast is not included in the iTunes Store podcast directory.

You give so little information it's not possible to essay a specific answer. Was your podcast in the iTunes Store prior to this? What is the Store page URL? What is the feed URL?

Until you post those I can only guess, and give you a boilerplate (stock) answer: if your podcast was in the Store and is no longer, then it's likely to have been removed by the Store Staff. Unfortunately they don't usually give any reason. If your podcast is rejected on its initial submission, or removed once it's appeared in the Store, this can be for a variety of reasons - see the list at https://help.apple.com/itc/podcasts_connect/#/itc8a10a0c56. If you attempt to resubmit you are likely to be told that the feed has already been submitted (submission of a previously submitted feed URL or podcast title is not allowed). What you do about it depends on the reason for rejection.

Obviously you must first locate and deal with the problem. In some cases, such as difficulty accessing the feed or media files, being in the wrong category, etc., you can go to Podcasts Connect and resubmit your feed. However some reasons for rejection will mean you cannot resubmit the podcast and it will be dimmed out in the dashboard at Podcasts Connect. In this case you will either have to contact Support and request reactivation, or change the feed URL and the podcast title and resubmit it as a new feed (which will lose any rankings, reviews, etc.). To contact Support go to https://itunespartner.apple.com/en/podcasts/overview and click the 'Contact Us' link at the bottom of the page.