In that case, the problem lies with the subreddit, not reddit in general.

In good subreddits, moderators will make sure eachother don't go too far; other moderators can see all actions you do in a nice interface.

I wish, though, that the moderator actions log was open to the public. That way, people could see which one is abusing their power and get some traction to get that mod removed.

In any case, you can always go create your own competitor.