But Zeng outgrew the stereotype of the docile and “disposable” peasant girl who comes to Shenzhen to work slavishly for a few years, then retreats quietly to her rural village. She stayed on at the factory, married a co-worker and returned to the plant floor after giving birth and sending her daughter home to be raised by grandparents.

Zeng worked without complaint, even as her work hours increased steadily. During the past two years, she said, she has worked at least 12 hours, and sometimes up to 16 hours, a day, going for weeks at a time without a day off. She liked the idea of making extra money—but she also believed she had no choice.

“Too much overtime ruins your life, and toward the end I was tired,” said Zeng, a small, wiry 29-year-old. “But the factory rule was that if you refused overtime three times you’d be fired.” Zeng said the factory handbook referred only to general worker compliance, but she believes the message was clear.

Seagate, which acquired the Shenzhen facility in 1996, terminated Zeng and most of the factory’s 1,400 workers at the end of March, moving the bulk of the production to a new factory in Wuxi, north of Shanghai.

The layoffs would have been unremarkable if Zeng and one of her colleagues had not noticed something wrong with their pension accounts.

It turned out Zeng was among 890 Seagate workers, all hired through the same labor broker in Zhuzhou, with the same problem. Their pension premiums had been set aside over the years, but the funds allegedly were not invested into accounts through the Shenzhen pension office.

They did something that can be risky for laborers in authoritarian China today: They organized and filed a grievance. Seagate did not respond to their complaint, even after they hired a Chinese lawyer, who was rebuffed by the local government agencies he approached for redress, according to documents obtained by the Mercury News.

Zeng maintains that the pension cash-out she received, along with her standard severance pay, was thousands of dollars less than what it would have been had Seagate enrolled her in Shenzhen’s social-insurance program, as her contract stipulated.

“I want the president of Seagate to know about this,” said Zeng, trembling as she spoke through an interpreter outside the gate of her old factory. “I’m angry with Seagate. Social-security insurance is about my future, and I was cheated.”

Seagate did not respond to Mercury News questions about the pension funds. But a company official issued a statement addressing the overtime controversy.

“It came to our attention that there were circumstances in connection with our operations in Shenzhen that were not in compliance with overtime requirements,” the statement said. “We are taking aggressive action to correct any issues, and are committed to maintaining compliance and continuing to ensure a safe and positive work environment for our employees.”