When a state agency informed the private probation company working for Atlanta Municipal Court it had no authority to charge $20 “enrollment fees” to thousands of people with traffic fines and ordinance violations, the company pulled out.

But it never refunded the unauthorized fees flagged by the state that it used to bolster its revenue, according to attorneys with Atlanta's Southern Center for Human Rights. Now, the center wants Sentinel Offender Services, one of the largest private probation companies in the country, to pay the money back.

On Wednesday, the center teamed up with Atlanta's Caplan Cobb to file a proposed federal class action against the private probation company and three of its Georgia executives. The suit was filed on behalf of potentially thousands of city traffic and misdemeanor offenders, many on limited incomes, who it claims were forced to pay Sentinel's fees because they were too strapped for cash to pay up-front traffic and local ordinance violation fines.