By Kurtis Ming

SACRAMENTO (CBS13) –Walmart tops the list of Fortune 500 companies, bringing in the most revenue.   Our hidden camera investigation uncovered a practice that may be adding to those profits.  It has some customers and consumer advocates outraged.

READ MORE: Firefighters Battling 350-Acre Rice Fire In Nevada County; Some Evacuation Orders Issued

 You give someone a gift receipt when you’re not sure if they’ll like your gift.   It could be the wrong size, a color they don’t like or maybe they just want something else.   For many, the gift receipt takes some stress out of gift giving.  It doesn’t state how much you paid, but you give it to them so they can get the full value if they return the item.   We’ve learned that doesn’t always happen at Walmart.

 “That’s totally wrong,” David Schmitz of West Sacramento said.

 After changing his mind about giving a make-up kit as a gift, he tried to return it to the West Sacramento Walmart store with his gift receipt.   He says the clerk was only going to refund him half of what he paid, because the item had since gone on sale.

“I bought the item, I paid for it.  I paid $15.  I didn’t pay $7.50.”

 His original receipt proves it.  After arguing a gift receipt and regular receipt should work the same, the store manager refunded him his full $15.

“But the average person isn’t going to know,” he says.

 We wanted to know if David stumbled across a secret at Walmart, so we sent in an undercover producer to buy a series of items at various Sacramento area Walmart stores around Valentine’s Day, St. Patrick’s Day, and Easter knowing these same items would most likely go on sale after the holidays.

The pillow and blanket we bought at the West Sacramento Walmart store for $10 before Valentine’s Day, only got us $5 back when we returned them at the same location with a gift receipt.

We only got $4.50 for pajama bottoms we bought for $9.

 “That’s a little shady,” a shopper said outside the store.

 We returned two St. Patrick’s Day T-shirts we bought for $8 to the Walmart store off Truxel Road in Sacramento.

We paid $8 for each of those shirts, but only received $4 back for each of them when we returned the items with a gift receipt.

 After spending $13.75 on Easter items at the Walmart on El Camino Avenue in Sacramento County, we only received $7.96 back after the holiday.

READ MORE: 'We're Going To Push The Envelope': California Takes Aim At Supreme Court's Concealed Gun Ruling

Add up everything we bought, we spent a total of $51.82 with tax, but only received $26.99 back when we returned the items with gift receipts.

The various Walmart locations kept $24.83 of our money.

“It’s a rip-off,” a shopper said.

“I do think it’s stealing,” said another.

Just to make sure it wasn’t isolated to our area, our sister station in Philadelphia conducted a similar test with a gift receipt there and got the same exact results.    When the clerk wasn’t willing to refund the full price paid, the producer asked the clerk if she would know how much was spent on the gift.  The clerk responded, “No, I don’t.  I’m telling you…. when I scan this and I scan that, that is what comes up”.  

Sacramento consumer attorney Stuart Tally believes this is an ingenious scam saying Walmart has got to be making hundreds of millions of dollars off this practice. 

“What Walmart knows is the person who gave the gift will never tell the person who received the gift how much they paid and they know the person who returned the gift will never report to the gift giver that they returned the gift.”

 We repeatedly requested an interview with Walmart’s corporate offices wanting to know why this is happening, for how long it’s been going on, and how much more money they’ve brought in using this practice.  They declined our request, issuing this brief statement.

We are committed to customer satisfaction and apologize for any inconvenience to our customers. It is our practice to refund the original price paid to the customer when returning an item with a gift receipt. We will be communicating with our store associates to reinforce our practice.  If a customer has a question regarding a gift receipt, we encourage them to speak with a member of management.      -Ashley Hardie, Manager Media Relations

 So it seems Walmart is blaming its sales associates.   Remember though, our hidden cameras caught this happening not only in the Sacramento area, but across the country.

 Kim Brown with the Department of Consumer Affairs says this is the first she’s heard of this type of behavior with a gift receipt.   We wanted to know if it was legal in California. 

“California state law is silent on gift receipts,” Brown said.

David Schmitz hopes what happened to him, will help protect others at the nation’s largest retailer.        

“I would never get a gift receipt from Walmart because it’s basically useless.”

MORE NEWS: Teen Shot In Head On Lodi Freeway; 3 Arrested

 We also randomly checked Target and Old Navy stores, and received the full value back when we returned items with gift receipts after they went on sale.  Our investigation is already getting attention at the State Capitol.    We’ll share it Friday, May 13th on the CBS13 News at 10pm.