They're not going to refund your money. Due to people making illegal copies of movies, a policy was enforced to not allow refunds of this item (as well as video games, music, software, etc). It's not just Walmart it's everywhere. I'd suggest watching trailers of movies to see if they're worthwhile or read reviews. The receipt might have been due to low ink in the printer or other. You can also upload your Walmart receipt on the mobile app so if you lose your hard copy, you will have it digitally.
Did you let Wal-Mart know that you can't read it? If you did and they gave you that copy. Than you can go back in and let them know.
If the movie was opened, Walmart will only exchange it for the same title. The only suggestion I can offer is to take your receipt and the movie in and speak to a manager. It's just policy. The same goes for video games
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