You should have just zoomed by when they weren’t looking, and grabbed a package or two out of their cart/buggy and kept moving. Anything they said, ignore them. They haven’t paid for it yet, so it isn’t theirs. And they’re hoarding.
LoL! - liable to set off a general riot, though. I HAVE heard of some fights & scuffles occurring at the Walmarts around here, which is pretty uncommon for around here, but over what exactly I haven't found out. The hysteria is getting ridiculous.