'I should have been able to leave to go to the ER and not worry about losing my job,' one employee (not pictured) said. Reuters Walmart, the single largest employer in America with 2.3 million employees worldwide, has come under fire for its attendance policy.

Based on conversations with Walmart employees and results of a survey of more than 1,000 current and former

Walmart employees, worker advocacy group A Better Balance issued a report Thursday claiming the retailer has punished its workers for taking sick days and time off to care for loved ones and violated a number of worker-protection laws including the Family Medical Leave Act (FMLA).

"Walmart should fully comply with the law so that no one is illegally punished for a disability-related absence or for taking care of themselves or a loved one with a serious medical condition," Dina Bakst, founder and president of A Better Balance, the advocacy group that prepared the report, told the New York Times.

Among the complaints A Better Balance received, employees have said they're afraid to call out sick, they've been penalized and even fired after taking sick time, and they face financial ruin as a result.

Randy Hargrove, a spokesperson for Walmart, issued a statement to Business Insider in response to the report:

"Like any company, we have an attendance policy that helps ensure our customers are being taken care of and that our associates are protected from regularly having to cover other's work duties. This policy requires that all of our hourly store associates be on time and work their scheduled shifts and manages against excessive absences.

"We understand associates may have to miss work on occasion and we have processes in place to assist them. This includes legally protected and authorized absences, such as medical-related accommodation, FMLA leave, pregnancy and bereavement, that are not counted against our attendance policy. Associates may request a leave of absence or other reasonable accommodation at any time by talking with any salaried member of management or an HR representative. Each associate's circumstance is addressed individually, in compliance with company policy and the law.

"We have countless Walmart associates who successfully partnered with the company to authorize their absences from work. We believe we have the right training measures in place to help communicate our attendance, disability, and pregnancy policies to our associates."

Keep reading for more detail on some of the key points and quotes of the report: