There's this artist I follow called EAJ, he posts his music for free in different platforms but not in Spotify. He and the fans discovered that someone was profiting off his art by posting it and profiting off it in different platforms and want to take it down ASAP
I tried to check and the only thing I see about reporting songs is "report music infringement"
Thanks for the post, In this case the best case of action would be for the Artist or an representative, to reach out to Spotify by using that form that you have mentioned and they'll be able to investigate due to the type of the claim and as a rights holder.
Any claim like this received by Spotify, is investigated on a case-by-case basis. Spotify however are unable to respond directly to each individual report, but will use their discretion and remove any content deemed to require removal.
However, I have seen that some content relating to the artist you have mentioned has been removed from Spotify from what I am seeing when search that Artist on Spotify.