Hi, I am trying to write a line to the CSV using Class::CSV. but I am not able to write it to the file.

Take a look inside, it doesn't support writing to files :) It also has no actual tests -- I would ditch this module in a hurry

OR should I be using any other module on CPAN like Text::CSV

Seeing how you're not using any of the methody-classy-ness of Class::CSV, and seeing how Class::CSV is unfinished and untested, yeah, stick with Text::CSV, it does everything you're trying to do