I have absolutely no reason to doubt what you are saying and what the Parent just stated. After my G12 in Zambia, that concluded all my Zambian education. So I am definitely not a voice of authority when it comes to this subject.
But I hope you understand where I am coming from when I say this story in unbelievable in more ways than one. When you argued with your professor, I don't know if you used derogatory language or questioned the contents of his pin-head or made any such unflattering remarks. But where I went to college, professor usually encouraged students to make arguments and question things that didn't make sense to them. If there was any favoritism in my college classes, it was toward the loudest students in the class. If you simply sat in your corner with your head down and never said a word the professor were most likely to grade you purely on your written work with no other favorable consideration.
But besides the lecture hall, the other unbelievable side to this story is the general public at large. How can such an injustice allowed to flourish? Very common, as you stated? Why? Is the Zambian people's complacency allowing this filthy behavior by professors to flourish? Is it that too many students choose to give in rather than fight? Any way you look at it, it's unacceptable for a student to be made to repeat a whole year or semester and to pay for it because of the fault of the school. It's preposterous. It’s insane.
And this losing of exam papers, how does that happen anyway? In all my college years, I don’t recall hearing even one incident of a professor losing a student’s exam paper. I attended a total of four colleges, bi-coastal. One on the atlantic coast and the other three on the pacific. But never heard of one incident of a lost exam paper.
What those Zambian professors are doing is totally unacceptable. But I really think it might help if the victims stand firm and not give in. Perhaps that's easier said than done. I will repeat that I am the last person to offer an expert opinion on this. But that is still my opinion