Problems in a dojo
About two years ago, two of my colleagues were taking a 1st kyu exam, and I was their uke. During their exam I wasn't aware that I made one mistake regarding dojo etiquette (I was sitting in the wrong place) because no one ever told me it was wrong. After their exam ended this guy approached me and in front of everybody told me about my mistake in a way "Are you crazy, do you know what you did...!?" He then turned his back on me and walked away before I had the chance to tell him that I didn't know about this rule. Then I called him by his name, and he turned around and said "Who do you think you are to call me like that!"
What's worse, later I told our dojo cho about this incident. He told me he'll investigate it. And a few days later he told me he talked with this guy and that the problem wasn't this guys behavior, but the main problem was in the way that I tried to get his attention when he turned his back on me when I tried to explain.
Sometime in May this year, there was this martial arts demonstration, and our dojo was invited to participate in it. This guy was the leader of our demo team, and since I wasn't in the demo team I took my camera to take some photos for the club (to put on our web site) and I also took pictures of other demo teams. At one point before the demonstration began, i approached this guy and asked him if he could gather the demo team so I could make a group photo. His reaction was literally "What do you want with this camera!? You think entire world is revolving around you because of it?", and after the demonstration he approached me and I had to listen various insults from him, most of them were (among other things) about my behavior (that I don't know how to behave). And he even proposed that if there's a problem we solve it with a fight...
Of course, once again I reported this to our dojo cho, and his response was "Uh you have to solve that problem with him". Is this just me or this guy has no interest what's happening in the dojo?
Just a few more things about this guy that gives me a hard time...: Many times I had to practice with him he was very rough when he applied techniques on me, and when it was my turn I couldn't apply any technique on him because he resisted by brute force. After that his explanation was often something like "Uh, that's wrong, but you'll learn it someday." My other colleagues also complained about that... And of course he is bigger and stronger than me.
And by the way, this lack of interest (or ability) of our dojo cho to do something about all this situation (this black belt guy that is harassing me) is literally killing my desire to continue practicing, not to mention that I feel very uncomfortable in class especially if this guy is present or even leads the class (i leave the class if he's leading it).
Any advice what to do?