By Kurtis Ming

After we exposed Wal-Mart Inc. stores nationwide for shortchanging some customers using gift receipts, Sen. Barbara Boxer sent two letters to the Federal Trade Commission requesting an investigation.

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FTC Chairman Jon Leibowitz is up for a second term and Sen. Boxer used Tuesday’s hearing as an opportunity to bring up the fact she wants to hear something.

“I’ve written you a couple of times,” she reminded Leibowitz at the Senate Committee on Commerce, Science and Transportation hearing.

Holding up two fingers, Leibowitz acknowledged receiving her letters about what we uncovered. We launched our investigation earlier this year after West Sacramento’s David Schmitz said Wal-Mart tried to short him half his money when he returned an item using a gift receipt.

“It’s basically stealing. They give you a receipt and they don’t honor the receipt,” Schmitz said.

We and other CBS stations tested stores across the country and found it wasn’t just David. In one series of tests, we spent $106.85 at Wal-Mart stores but got less than $63 back. Wal-Mart kept $44.53 of our money.

“I thought it was more than that,” a producer with a hidden camera told the clerk.

“It probably was, but you don’t have a receipt with the actual price. I have to give you whatever comes up,” the clerk responded.

Wal-Mart blamed its workers for not following company policy and sent out a memo to its 3,800 stores reminding management to refund the original price paid. When we returned this summer conducting more tests, Wal-Mart shorted us again.

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“It’s just like somebody going and picking somebody’s pocket,” Sen. Boxer said during the nomination hearing.

She wants the Federal Trade Commission to investigate and take action.

“Mr. Chair, it would be as if I went out and bought you a Christmas gift or birthday gift and spent $35 and you bring it back and you get back $15 and you say ‘what a chintzy colleague I have there,’” she said.

The crowd laughed out loud.

“The point is that’s out and out theft,” Boxer said.

FTC Chairman Leibowitz did not respond directly to Boxer’s remarks, but during his nomination hearing for a second term, she made her point clear.

“I would hope in the near future we would see a response from you on this,” she said. “It’s very disturbing.”

Wal-Mart maintains it’s company policy to give you back the price you originally paid when using gift receipts. We want to know if they’ve improved. In time for the holidays we are testing Wal-Mart again, and several other major stories.

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We’ll have the results Friday, on the CBS13 News at 10.