Is this a glitch?

On the day after Black Friday, my local Walmart had a sign stating that select video games is on sale for "$15." When I cashed out those titles, they tried to charge me full price.

When I pointed to the sign they stated that sale price was valid for yesterday only, and refused to make a price adjustment. Their sign had no valid date. By the way it's illegal in some states for stores to deceive their customers in such a manner. Walmart could not be reached for comment regarding this experience.

The person next to me stated they only have $30 so they spent a lot of time deciding which games to purchase, only to be charged full price for those items.

To make matters worse, I needed to wait in a long line just to leave the store because they couldn't handle checking everyone's receipt.

Anyway, it's a good thing they refused to honor their sale prices, because I found better deals on Amazon.com; for example, I purchased Horizon Zero Dawn: Complete Edition for only $9.99.