Just mute them. I normally don't resort to that, but there was this person that was doing over and over and I had to mute, otherwise, I would have to unfollow. What some people do not realize is that there is a fine line between trying to engage and spamming. When it crosses the spamming line, people will start reacting badly. Later they start to loose followers and seems oblivious to why and post some more "Please follow me, why no one sees my post."