My 3DS bit the dust

[Petie]

Walmart often does take back products without receipt for store credit. Given how recent the purchase was, they might even have a record of it on their end but since you're past the return window it may be better to just try returning it as defective and say you lost the receipt. Worst case scenario, you're in the same position you're in now.

Also, Club Nintendo would be no use to you now - I'm pretty sure they've stopped allowing new registrations anyway. You might be able to deal with Nintendo directly though I can't remember how long their warranty lasts.