Starbucks is under fire for failing to improve working conditions for baristas.

But baristas aren't alone — store managers are also facing a difficult environment, according to one Chicago-area Starbucks manager who worked for the company for 10 years.

The manager, who asked not to be named, said she was under intense pressure to reduce payroll costs, and that her supervisor regularly asked her to manipulate time sheets – which meant that some employees weren't paid what they were owed.

“Starbucks was chaotic,” she told Business Insider. “The training was chaotic. I am a self-starter, so I managed to train myself for the most part. I had assigned classes that I took, which I don’t remember much from, but most of my training was on the floor, learning from the baristas and shift supervisors.”

The former manager asked not to be named because she said she is in the process of suing Starbucks for alleged wrongful termination. Business Insider verified she was a manager through public records.

During her first couple of years at Starbucks, the ex-employee said she was repeatedly assigned a new supervisor.

In just the first four years, she had five different district managers, she said.

Her fifth supervisor stuck around, but was extremely difficult to work with, she said.

“Over the next six years, my relationship with her was volatile,” she said. “She would give me corrective actions for the most absurd reasons. She would make us train our shift supervisors to do our job, yet they would not get compensated for it.”

For example, she elaborated, "When it seemed the training hours were used up, the [district manager] would tell us to put someone who was clearly training under a different time code."

The supervisor also prevented employees from taking time off when the store was busy.

“If your business requires it, then you have to work,” the ex-manager recalled her supervisor saying.

“I couldn’t take Saturdays off, and I am part of a Messianic Jewish Congregation. I could not observe Shabbats,” she said. “My previous [District Managers] allowed me to do it, and I worked on Sundays, but she said I have to work on Saturdays. I was terrified of her, so I did it without complaint, because I was always under the threat of being fired by her.”

The former manager said she was also under intense pressure to reduce payroll costs.

At one point, she said she was reprimanded for logging too many training hours when she was opening a new store and forced to ramp up her staff from 12 people to 23 people over the course of three months.

“Because the company ‘overspent’ in the first quarter on a roll out of a new program, they were asking all of us to cut labor,” she said.

When reached for a comment, a Starbucks spokesman said, "We deeply care about all of our partners (employees) and are very concerned to learn about this former partner’s situation. The experience described in this case is not acceptable and is not consistent with our values and practices. We would like to learn more so we can look into her situation and address her concerns."

During the course of her employment, the ex-manager signed onto a class action lawsuit accusing Starbucks of failing to pay managers overtime.

Starbucks settled the lawsuit for an undisclosed amount.

It’s one of a number of lawsuits Starbucks has settled regarding overtime pay.

In May 2013, for example, Starbucks agreed to pay $3 million to resolve a class action lawsuit accusing the company of denying employees required meal breaks and issuing inaccurate wage statements.

Starbucks has vowed to do more to improve working conditions for its employees, calling specifically on managers to give baristas more consistent schedules.

"To our store managers, I want to stress that as we continue to evolve and improve the usability of our system, we have to go the extra mile to ensure partners have a consistent schedule — free of back-to-back close and open shifts that are less than 8 hours apart — that is posted 2 weeks in advance," Cliff Burrows, Starbucks group president of the US and Americas, said in a memo to employees last week, CNN Money reported.