Cannot log in to Dashboard

My wife has tried to get her domain listed for sale on Flippa.com. After she attempted to do what she was instructed, we can no longer log in to the dashboard. I’m not entirely sure what she did, but i’m guessing it was css editing or similar. When we do try to log in to the WordPress dashboard for my wife’s domain we get redirected from the regular /wp-admin to /flippa_3117008.txt/wp-login and see this: “Error 404 – Not Found

The document you are looking for may have been removed or re-named. Please contact the web site owner for further assistance.”.

And, in order to get Sweepingtheusa.org fixed so we can get it listed, we’ve been instructed to do the following: “Our normal ownership verification system requires either a text file as you’ve mentioned or a meta tag in the site’s main landing page, usually at index.html.”. But again, we cannot get into the dashboard to make the changes. I think we might be at a dead end, considering our host cannot do anything since the “error” is on the backside (dashboard). Please help!!