Last few months someone (I'm sure that this is the same person each time) constantly downvotes my answers. Of course with no comments.

Maybe someone offended on my criticism or someone who think that SO is a game where you can win so downvoting "competitors" is OK approach to get to top...

Anyway, I've left flags several times, but I got only "helpful flag", "we'll check", "investigation in progress" from moderators...

Nearly two months passed - the "joker" is still not banned

So is it OK to, for instance, to remove already accepted answer which was downvoted and post the same?

Or is there any other way to resolve this kind of "conflict"? Any suggestions?