What does this mean?

OK. I created a post about "32 words that can change your lives". 

@cheetah detected a copy of it somewhere else on the Internet and alerted me. So I edited it. Changed the topic and the body of the post, but the URL of the new post is still showing the title of the original story which I posted: https://steemit.com/wealth/@chaching/32-words-that-can-change-your-lives.

I even tried to delete the post by changing the topic to "Deleted" and typed in "To post under new tag" as the body of the post, but I got this warning instead: "Transaction failed: comment.last_payout == fc::time_point_sec::min(): Dismiss"

How can I make the URL show the title of the new post instead? 

I understand STEEMIT does not have a "delete post" button, which can be frustrating when you want to update your posts.

Any useful suggestion would be appreciated. Thanks.