Following up on the ombudsman idea, if you decide to meet with the college head, it's a quiet show of strength to have an advocate sitting there next to you. This elevates the seriousness in a positive way. The advocate also acts as a fair witness.
I got this idea from extending something from Herb Cohen's You Can Negotiate Anything. And even heads of state often do this same thing. Of course, even the better methods of negotiation work only, say, two-thirds of the time.
Your advocate can be a family member, a former boss or teacher, or even a religious leader. The person just needs to be someone who believes in you and wants to see you get a fair shake. If you don't have a potential advocate, and there have been times in my life when I haven't, you can still do this yourself. Just the odds aren't quite as good.
It is a sign of respect to tell the college head of an ongoing situation, and you can even tell him or her this. And if you're undecided whether you want the situation rectified or want to request a refund, you can also tell the head you're undecided.
The assistant lecturer is a lout. With him participating in in-group/out-group behavior and cliques, I have a difficult time thinking the situation will be rectified. But, maybe. It's your call.