What should I consider when making a complaint centrally to the university regarding the quality of a subject? Background

I recently was enrolled in a science course where I believed that the lecturer had a really poor understanding of the material at hand. I have had some bad lecturers before but this lecturer is one of the most difficult academics I have ever dealt with. 

I was warned by all the postgraduates/PHD students to not take this person's course as it was poorly taught and it was incredibly frustrating raising fundamental errors made in lectures. Eg

Me:The projector says s &lt; t

Lecturer: No it doesn't (doesn't look at projector) 

It clearly did... I wasn't the only one that noticed it

The reason why I decided to take this course is because it happened to be related to my thesis area and I had studied it and taken similar subjects before. Ultimately I just wanted an easier semester. 

Anyway there came a point in the semester where I questioned a mistake made in the lecture and I said another result should have been used. The lecturer got out the result they quoted and the result I quoted in response on the projector. It was quite obvious that what they said wasn't correct but just said in response that I wasn't correct even when I quoted a reference. This prompted me to try and drop the course and use another course for credit.

Initial Complaint

Unfortunately when I tried to drop the course I was too far into the semester so  my other option was to make a complaint to the department. I really needed to graduate at the end of semester so I decided to take the course in the mean time but put in minimal effort to pass as I was so frustrated with everything in the course. I made this very clear to the department.

I approached the head of the department and made a complaint about the course.

I waited well over a month to hear back from the department and the department decided to not do anything because there was insufficient evidence. I certainly understand that it is difficult for them to make a conclusion.

However they also said that my grade was probably a reflection of the educational background that I had (what they meant was because I was already familiar with the area that due to differences in ways in how it may be taught it contributed to my poor grade). 

This really frustrated me. Ultimately I really regret letting my pride get in the way by not putting in any effort in the final. But at the same time I don't understand how the examples that I gave (which were the ones given above plus more) leads to that conclusion. I feel that they pretty much came up with their own conclusion as to what happened. I made a request that they should talk to the students (past and present) and see their experiences but it seems that they didn't bother at all. 

What I want to achieve 

I just want to remove that subject from my transcript and replace it with the other subject I have. It seems that the option that I have is to escalate this to the university and have it resolved centrally. This seems like quite a lot of effort and stress. A part of me feels like I am obligated to do this because so many of the postgraduates have had similar experiences to me. They choose not to complain to avoid awkward situations.

Another reason why I am quite reluctant is because if I was to make a complaint of this nature centrally to the university this would probably put the lecturer in quite a predicament.

I have seen similar questions posted here but ultimately what I am asking is what are some potential consequences for the lecturer assuming that my complaint is successful?
Finish the course, and let it go. It sounds as though you are being properly taught a lesson in taking a course you knew you shouldn't take. This is actually a lesson worth experiencing. Real life will require you to face unwanted tasks, in unpleasant situations, while being judged by a person that you know is not qualified to judge your performance.  So i suggest you simply get the best grade you can, and move on with your academic career. 

Good luck.