Can re-take exams be changed after submission?
As stated in the comments this varies widely based on where you are.  I'm going to assume that in your institution professor's exams are NOT subject to a significant review process.  &quot;Significant&quot; in this context means that the instructor is free to ignore the review, not that reviews don't happen.  As an example, I recently taught in a university where I was required to submit my exam for a check by a faculty member with similar skillset, to make sure that the exam is appropriate for the course.  In that institution I'd say that a &quot;significant&quot; review took place, since I was not really free to ignore the review.
In a case where such reviews are either optional or don't happen at all, the instructor will write the exam, give it, and grade it without much interference from anyone else, if there is any at all.  An exam with a 97% failure rate is exceptional in many programs, but perhaps not all.  I can speak only to engineering in Canada, and such a failure rate would absolutely raise questions.
The process depends on your school but usually there is a formal process of review.  This typically involves speaking to the person in charge of the program that offered the course you were taking.  If this was a course in your own faculty, then usually you'd have a chair of undergraduate education, or an &quot;academic administrator&quot; or something like that.  They would be the first person I'd talk to.
However, you will need to be sure that your evidence and requests are reasonable.  The best way to do this would be to state clearly and with solid evidence why this exam was not fairly written, and why a 97% failure rate does not reflect student learning.  The onus is on you here.  As an example, I hear students say &quot;XYZ was never taught, why is it on the exam&quot; so frequently but it is rarely true.  It may be the case that you missed it, or that you didn't understand the implications of something that was said, but that's different.
For each of the perceived issues you have with the exam, you will need to clearly find evidence that it is in fact an issue with the exam and not your understanding.  You will also probably need to drop some things because they aren't valid.  For instance, &quot;the exam wasn't like the homework&quot; is not valid.  &quot;We were examined on topic X, but the syllabus explicitly states that X is not part of the course&quot; is valid.