How to sue for Illegal fee collection by college

I live in ,Uttar pradesh. I study in a college affiliated to aktu,lucknow. My college is a private institution .I study Btech civil here .I have paid my full fees to the college After submission of the first installment of my fees on the second installment I saw an increment of 13000 rupees in my net balance. I complained for this to the college administration ,but no action is taken till now,they say they have imposed fines on me and will not remove it.Neither I have done any damage to college property nor any such information was given before imposing fine on me. Earlier also this college was illegally charging fees which was not mentioned in yearly fees.ii refused to pay ,they threatened to impose more fine on me . Now they are stopping me to give my sem practicals ,can they do this ,is it legal