Hey @deekayn.
Thanks for your question! Don't worry - although you can't 'un-delete' songs you've given a thumbs-down to while listening to a station, you can check your listening history on desktop by checking your Recently Played folder under Your Library.
Hopefully you'll be able to retrace your steps and find that song you listened to.
Hope that helps! Let us know if that did the trick for you 😉
Hey there you, Yeah, you! 😁 Welcome - we're glad you joined the Spotify Community! While you here, let's have a fun game…