This is how you can block someone on Spotify

Spotify is more than a music streaming service. Today, Spotify also includes many social features. For example, you can link your Last.fm account to the streaming service, so you can accurately keep track of what music you’ve listened to and how often. You can also create playlists with friends and you can follow friends. If you want to prevent someone from following you on Spotify, you can block him or her.