WalMart now is tougher on returns than Target! At least mine is! They used to take things back, no questions asked. Well, I had to return a carseat I bought, couldn't find the receipt. I had not even opened the box. I brought my credit card bill with the purchase listed on it because I didn't have the receipt. They couldn't look it up based on the card I paid with (which Target can do in seconds). They wanted to know what day and time I made the purchase AND which checkout lane I went through!! It was crazy. They ended up giving me a gift card because they couldn't credit my card since I didn't have my receipt. Lesson learned. Wal Mart's return policy stinks now! (and I found the @^!%@$ receipt a few days later at home! I knew I had it somewhere!)
Apparently their policies vary by store. My WM would have taken the seat back, no questions asked. You would have received a gift card, not cash (but if you'd taken it back 12 months ago, you'd get cash!) I guess mine is pretty loose!
Really, you don't know? Because scammers make a living off of returning and rebuying and returning,etc. Stealing items and returning for cash. Using an item and returning it for a new item.
I told my boss I had to "burn" my last Target return on those diapers, so if I need something returned in the next year she will have to return it for me! 

I should have done the return all at one time but I didn't (I kept forgetting) and now I have to have a receipt (which I normally do). Luckily I hardly shop at Walmart so it doesn't really bother me but it did make me laugh when I got blacklisted from Walmart. I'm not sure how long it lasts either LOL!