You should have placed the order with Monoprice before you stepped out the door on your way to H.H. Gregg. Worst case, you'd have a few cheap yet good cables on hand for the next time (so, maybe you should keep the Walmart cables as a reminder?); best case, you could sell 'em on ebay for a killing (pretend you're made of brick & mortar!
"...but ya doesn't hasta call me Johnson!"