how do i delete unplayed podcasts from a windows 7 pc running itunes 12.4.1.6

iTunes version 12.4.1.6 running on a Windows 7 PC shows 34 unplayed and 17 saved episodes. I want to delete several of these. I clicked on the circle with three dots next to each episode. Generally (not every time?!) I got s dialog box asking if I wanted to delete the podcast. I answer yes, the dialog box disappears, but the episode is still there. Then I clock the circle with three dots again, click delete, and that episode disappears from the list. This process worked on most of the episode. Three would not delete at all. Several others didn't present the "Are you sure..." dialog box. Buit I did get down to 3 episodes. Then I pushed the "refresh button", and all of the episodes that had deleted showed up again on the list. I"m back to 34 unplayed and 17 saved!

Help!