same thing happened to me, i wanted to get a big upvote so i followed minnowbooster's voting power, and when the power came to 57% i knew its going to start voting, so i kept sending one after another, because i missed it before, and this day was the last to take vote on that particular post. i did it manually in the website, i get it that i shouldn't have done that, but as you said its really hard to get a big upvote,
and i got blacklisted,
then i was kicked off the discord server....

now, lets see if i can get on smartsteems whitelist........
minnowbooster was the best though