@ideasmithy@mastodon.social Depending on your client (browser or smartphone App), somewhere near that post you will find 3 dots. It's a menu that contains the 'Report' button that communicates the abuse to the admind of your Instance and eventually to the admins of the Instance of the abuser.
After reporting the post you can block the user.
Take a look of the name of the Instance of the abuser. If you will notice in the future that more that one abuser comes from the same Instance, you could decide to block for yourself the entire Instance and also propose to your Instance admins to block it for everyone. @citrustwee @Gargron