Walmart is holding a three-month "Rollback" on iPhones and Galaxy smartphones.

Starting Friday, customers can save $100 on all Apple iPhones or $150 on all Samsung phones through the end of June.

Not every store will carry the same models, but the discount applies to all of the latest devices -- including the iPhone 6, 6 Plus, 6S, new four-inch SE, and the Samsung Galaxy 6 and 7.

Over the past month, customers have contacted CNN about this story. They said that local Walmart stores were not honoring the discounts.

Walmart told CNN in a statement that the company failed to communicate the Rollback successfully to its staff.

"We were so excited to help our customers save money on the Apple iPhones and Samsung Smartphones that we got a little ahead of ourselves and had a mix-up with notifying our store associates in stores," the statement says. " We apologize for the confusion, and you can rest assured that these deals are available to customers."

Walmart is working with AT&T (T), Verizon (VZ) & Sprint (S) on the deal, so customers will see the discounts through their bills. Unfortunately, T-Mobile (TMUS) customers won't be able to take advantage of the promotion. The deal is also not available for online purchases.

Spokeswomen for Verizon and AT&T told CNN on May 10 that customers should see bill credits in two to three billing cycles.

A Sprint spokesman said that a "service credit is applied 45 days after the device is activated. (S)ince the promotion began on April 1, the soonest any customer would receive a credit is May 15."

Related: Apple announces four-inch iPhone SE

Apple (AAPL) launched its newest iPhone -- the SE -- last week. At $399, the 16 GB model is the cheapest smartphone in the company's lineup.

The SE becomes an even more attractive option with the Walmart discount -- especially for people who want a newer iPhone but don't want to spend half a grand.

The SE looks nearly identical to the iPhone 5S, but takes better photos and videos, and has the same A9 chip and M9 motion processor as the newer iPhone 6S.

Updated on April 13 to include statement from Walmart.

Updated on May 11 to include statements from Verizon, AT&T and Sprint.