I changed my username from something I used years ago to the new blog I wanted to start. Along the way, I was given a few options about how to handle the new blog, and I went with:
"Change example.wordpress.com to match my new username and discard the old address” will change the address of your current blog. If your new user name is newusername, your blog’s address will be changed to newusername.wordpress.com."
...assuming that it made more sense to reuse the space I already had than to create a new blog.
But, unfortunately, I didn't realize that, since I deleted my old blog, now my new blog is automatically deleted before I even started it. Visiting the address gives the "Authors have deleted this blog" error message.
I know that there isn't a way to undelete a blog, but that's not really what I need to do. What I need to do is detach my new username from my old one. Any ideas?