(CNN Money) -- Sam's Club shut down multiple locations on Thursday, and some employees and customers say they did so without warning.
Walmart, which owns Sam's Club, did not respond to numerous requests for comment.
Workers and customers learned about the store closures on the same day Walmart drew praise from the White House for raising pay and giving out worker bonuses because of the new lower corporate tax rate.
The retail giant is boosting its starting pay for U.S. workers to$11 an hour; the federal minimum wage is $7.25 per hour.
There's also a bonus of up to a $1000 for eligible employees who have been with the company long-term. Walmart is also expanding maternity and parental leave benefits.
Customers took to social media with questions about why their local Sam's Club stores were shuttered. Some demanded refunds for their Sam's Club memberships, which cost between $45 and $100. The official Sam's Club Twitter account replied to some questions with a brief statement.
"After a thorough review of our existing portfolio, we've decided to close a series of clubs and better align our locations with our strategy," Sam's Club wrote in one reply. "Closing clubs is never easy and we're committed to working with impacted members and associates through this transition."
Employers must give workers 60 days notice before closing a plant or issuing mass layoffs, according to the Worker Adjustment and Retraining Notification Act. Sam's Club posted one such alert, referred to as a WARN notice, to the Indiana state government's website. That notice says three locations in the state were slated to be closed on January 26. The move will impact 419 employees.
Several other states where CNNMoney has confirmed stores will be closing did not have such notices posted as of Thursday afternoon.
It's not clear how many stores have closed. Local news outlets across the country reported the closures happened without notice.
A reporter in Houston said via Twitter that employees at one local store showed up to work and learned the location was shutting down.
Syracuse.com reported multiple locations in upstate New York have closed. Fox 13 in Memphis said its local store has permanently shut its doors, and that employees only learned of that Thursday. Another report from WFAB says a location in Baton Rouge was shut down.