A former vice president at AMC Theatres filed a federal lawsuit on Wednesday, accusing the company of firing her after she complained that she was paid far less than her male peers.

Tonya Mangels, who was vice president of product marketing, said that in March 2018 her supervisor inadvertently sent her a spreadsheet that included her co-workers’ salaries. She discovered that the male vice presidents were earning 56% to 72% more than she was, according to the complaint.

Mangels raised a concern about her pay with HR the following month. She said she was later assured by her boss, chief marketing officer Stephen Colanero, that she would get an increase. “AMC knows that it needs to make an adjustment,” he told her, according to the suit.

Six months later, seeing no movement on the issue, Mangels put her concerns in writing, asking the company to formally review her compensation and bring it into line with the other VPs. Following that letter, Mangels alleges the company began to retaliate against her.

According to the suit, Colanero took his direct reports out to a holiday dinner in late 2018 but excluded Mangels. In February 2019, she got a review which asserted that her overall performance “does not meet expectations.”

The suit alleges that Mangels had received high ratings ever since joining the company in 2009. She said she confronted Colanero, who told her that he was trying to “send a message” to her. She countered that AMC needed to address the wage disparity, and brought up the spreadsheet.

“Mr. Colanero became upset when he learned that Plaintiff knew about the information reflected in that spreadsheet, and he told Plaintiff that he ‘did not intend’ to send her that information,” the suit states. “Despite that frank conversation, nothing was ever done about the wage disparities, and no productive dialogue ever occurred on the issue.”

According to the suit, Mangels’ bonus was slashed in half. She filed a discrimination complaint with the Equal Employment Opportunity Commission in May.

In August, the suit alleges that the company launched a sham investigation into whether Mangels leaked word of impending layoffs to her marketing team. Mangels said she had no knowledge of the layoffs before the general announcement, and therefore could not have leaked the information. Nevertheless, she was informed on Sept. 30 that she was being fired as a result of the investigation.

“Plaintiff was actually fired because of her sex, female, and because AMC retaliated against her for engaging in protected activity on multiple occasions,” the suit alleges.

Mangels is alleging discrimination and retaliation in violation of the Equal Pay Act of 1963. AMC did not immediately respond to a request for comment.