Part of going to college is learning to be a responsible adult, being accountable for the consequences of your decisions, and knowing exactly what you are getting into. You need to ask lots of questions and research what you need to know instead of assuming someone will spoon-feed you the information. By signing up for classes, you enter into a contractual agreement and are liable for payment of tuition and all other terms of that contract; you can't just hope it goes away if you didn't take action to drop the classes before the deadline. Sounds like your friend didn't fully understand what the couselor told her, and should have read the policies in the catalog:
"Students may drop a course and receive a refund up until the 'last day to drop with a tuition refund' (census date) as noted on the academic calendar. Students who change their mind about taking a course must drop the course and process the drop online through NOVAConnect. Otherwise, the student will be charged for the course and may receive a failing grade."
http://www.nvcc.edu/catalog/cat2013/enrollment/courses.html
"Students should not assume that they will be dropped automatically from classes for which they have not paid. Students must drop all classes they do not want to take and confirm their schedule of classes before the end of the add/drop/swap period to assure their tuition bills are what they expect."
http://www.nvcc.edu/catalog/cat2013/financial/payment.html
The college will administratively withdraw you from unpaid classes and place a hold on your record, but that does not relieve the financial obligation to which you agreed by signing up. By reserving a seat in a class and not dropping it you are barring the college's ability to sell that seat to a paying student who actually wants to take the class.
"In addition, the College reserves the right to pursue payment through debt collection services and other lawful means. Debtors are subject to late fees and collection costs."
http://www.nvcc.edu/catalog/cat2013/financial/debts.html