Shriram City — About not releasing of NOC letter

I have took loan of 2lakh rs for period of 36 months, and EMI was 9055. At the beginning he had said emi will keep on reducing as on time, later he they said it is flat interest and emi will not get reduced. If I ask them the loan documents they have are not ready to give.so now I need to pay 126000 as interest for 3 years period, so I decided to close the loan, after 1 year I closed the loan and by one year I paid 12 emi and paid 159000 to close the loan, and still they are asking me to pay 40000 to get NOC, what can I do now, I don't have money now, and they said interest will keep on adding.