MANHATTAN (CN) – Starbucks discriminates against deaf people in New York City by refusing to serve them, ejecting them and making fun of the way they speak, 12 customers claim in Federal Court.

The plaintiffs, most of whom are deaf and use sign language, claim the discrimination occurred repeatedly at more than one Starbucks in New York City.

Plaintiff Alan Roth describes an August 2012 incident in which a Starbucks employee on Park Avenue South "stated that he sounded funny," asked him to repeat himself and laughed hysterically at his way of communicating.

He claims that when he asked to speak to a manager, the employee got angry and screamed obscenities in his face.

Then Starbucks employees asked Roth to leave and told him he was not welcome at that store, according to the complaint.

Roth claims he reported the incident to a manager, who failed to take action.

Lead plaintiff Lawrence Bitkower, who organized a monthly "Deaf Chat Coffee" meeting, claims the Starbucks store where his group met tried to kick them out before closing and refused to serve them.

"At approximately 9:00 pm, four hours before the posted closing time, a total of four Starbucks employees told the 'Deaf Chat Coffee' group that they had to leave the area they were occupying as it was going to be cleaned," the complaint states, referring to a December 2012 meeting.

"Once the 'Deaf Chat Coffee' group moved, the Starbucks employees proceeded to allow non-deaf customers into that area and did not clean the area.

"At approximately 9:00 pm, plaintiff Sean Finnerty ('Mr. Finnerty') waited in line and proceeded to try to place an order with a Starbucks employee by handing his written order on a piece of paper to the Starbucks employee.

"The Starbucks employee refused to serve Mr. Finnerty.

"Confused, Mr. Finnerty demanded to know why he was not being served.

"The Starbucks employee informed Mr. Finnerty via writing that Starbucks was not serving deaf individuals.

"Shocked, humiliated and disgusted, Mr. Finnerty reported what had happened to other deaf individuals of the 'Deaf Chat Coffee' and the manager 'Ziyad'.

"Plaintiffs Elvira Janturina and Miu Ng along with their two other friends who are deaf attempted to place an order with the Starbucks employee and were also refused service because they are deaf.

"Additional requests for service were made by plaintiffs Elvira Janturina and Miu Ng and were refused by the Starbucks employee as the employee continued to serve other non-deaf customers.

"Finally, plaintiff Elvira Janturina had to beg a non-deaf stranger to order for her and her deaf friends in order to receive service.

"Plaintiffs Lawrence Bitkower, Charles Kaufman, and Evan Dach spoke to Starbucks employee 'Ziyad' about their disgust about how the deaf were being treated by Starbucks. 'Ziyad' rejected their concerns and told them that 'Ziyad's' manager told him to not serve deaf individuals."

The plaintiffs claim Starbucks employees continued to discriminate against them during their next gatherings at the store.

When a Starbucks employee who knew some sign language tried to assist the deaf customers, she was reprimanded by another employee, according to the complaint.

To top it off, during a March 2013 gathering at the same Starbucks, the manager Ziyad called the police and falsely accused the plaintiffs of causing a disturbance, according to the complaint.

Police found no illegal conduct, apologized to the deaf customers and reprimanded Starbucks employees for calling them, the complaint states.

But instead of apologizing, Starbucks employees told the plaintiffs they were not welcome at the store and tried to intimidate them, according to the complaint.

After the plaintiffs sent an email to Starbucks CEO Howard Schultz and other upper management, a regional vice president apologized for the "inconvenience we caused you and your friends" and offered them a preloaded Starbucks gift card, according to the complaint.

But the plaintiffs claim the company took no significant action to redress discrimination, such as launching an investigation or sanctioning employees.

The plaintiffs seek an injunction and compensatory and punitive damages for violations of the Americans with Disabilities Act, and state and city laws.