Podcasts won’t delete

Podcast episodes won’t stay deleted. Over and over and over again I delete episodes of various podcasts—all of which I had originally decided to download, all of which I’d played, some I’m subscribed to, some I’m not—and when I check back, the episodes are still there. This has been going on for weeks. I’ve tried this hundreds of times. I’ve closed the podcast app, I’ve turned off my phone. I have the newest iOS. Nothing works.