Legal Help

Somewhere out there is a ~10 second snapchat quality snippet (my producer tag and all) of my song that was to be released. Someone had taken, no joke, this portion of the song and uploaded it to stores. Now my release is being held up by metadata. What do I do? I have the full song (around 2:30) and its original file, but not at my dorm. Could I find this person and sue? Can I prove the song is mine?