The federal government has accused Walmart of violating the Americans with Disabilities Act by firing an employee with Down Syndrome who could not adjust to having her schedule changed after 15 years on the job.

According to the complaint [PDF] filed yesterday in federal court by the Equal Employment Opportunity Commission, the employee had worked the same schedule from when she started at the store in 1999 until Nov. 2014.

That’s when her store in Manitowoc, WI, shifted to a computerized scheduling system that changed her hours.

According to the EEOC, the employee’s condition “requires that she maintain a rigid schedule of daily life activities,” and she asked store management to place her back on the hours she’d been working.

“Despite numerous conversations, Wal-Mart never offered to modify her schedule, or proposed any other accommodations,” notes the complaint, which contends that the store — a 24-hour “Supercenter” with 300 employees — could have returned her to her previously scheduled hours without experiencing any hardship.

When the employee began having difficulty keeping her new longer and later hours, the store disciplined, and then ultimately fired, her in March 2015.

Her mother and sister subsequently pleaded with Walmart management to rehire the dismissed employee, but to no avail. They then escalated their complaint to the EEOC, which eventually concluded there was reasonable cause to believe that the store had violated the ADA in firing this worker.

The EEOC notes that it communicated with Walmart in an attempt to reconcile the store’s questionable policy, but could not reach an agreement.

The government’s lawsuit seeks to have this employee rehired along with back pay and other compensation.

“Even the nation’s largest private employer must comply with the law’s requirement to make a good faith effort to accommodate an employee with a disability,” said Julianne Bowman, district director of the Chicago District.

In a statement to USA Today, a Walmart rep maintains that this employee was aware of her obligation to work her full schedule, but that she continually failed to complete her assigned shift even after being spoken to about the problem.

“We’re sensitive to this situation and we tried to reach an amicable resolution,” said the rep. “We remain open to continuing those discussions, but the EEOC has not acted in her best interest.”