I don't think colleges should be allowed to charge money for Rechecking papers

I study in Mechanical Engineering and I am 3 rd year and this is something from the past. I had backlog in Mathematics - 3 and I cleared it one sem later. My college is a Mumbai University Board. I studied really well and I expected my Minimum Score on my Kt (backlog exam) to be minimum 60/80. I only got backlog because dumb things I did during last exam. When I got my Result I only had score of 38/80. And I have heard rumors from seniors about giving lower marks to student and then way higher marks to students when they send paper for Rechecking. I didn't do that. But when I was talking to a friend who doesn't live in Mumbai. He said how it's wrong colleges charging money for this and I thought the same thing. Many colleges can run a scam like this? Where they purposely out low marks to get money from students for Rechecking and xerox copies. I am not complete aware of how these procedures work so if someone who knows it and I am wrong I will gladly accept criticism.