You can try contacting support, but it's going to be almost impossible to track down an account if you don't know the username.
It's worth a shot to contact support:
If you get an automated reply email, you need to reply back to it.
Support usually replies within 24-48 hours.
Hey there you,
Yeah, you! 😁
Welcome - we're glad you joined the Spotify Community!
While you here, let's have a fun game…