Anna University — college asking me to pay exam fees which i'm not attend

Address:

84,natha kollai street kodanagar., cheyyar., Tiruvannamalai, Tamil Nadu, 604407

My name is nagesh, arulmigu meenakshi amman college of engineering vadamavandal kanchipuram i ask our college to return my certificates but they ask money.
There are only three students in my class, due to my person issue like i'm the one to attend the class but it makes me lonely then i had depression over that i didn't goto college but attend the 2 semester but clear all paper so i was so depressed then i'm staying in home then i didn't inform our before exam that i'm going to discontinue but after third sem i went to the college to discontinue but they asking me pay full amount which i'm not attend classes, exam then i i formed dsa anna university but didn't solved completely now they asking me exam fees which i'm not attend but our college paid money for me without my confirmation

One more thing they are not respect dsa action over my concern because they told me like we can change the issue into more like threatening me
I'm responsible for their mistake but i'm not able pay fees