I bought a water softener at HomeDepot about three weeks ago. Initially went to my local Lowes where I had checked if one was in stock and at the store. Yes and Yes. Get to Lowes and there is no water softener, as the website indicated. Lowe's employee checked the back as well, wasn't there.
There are many problems with humans doing this "inventory business" at $10 an hour or so. The professional counts that happen once or so a year by outside agencies wouldn't be necessary otherwise.
To be fair, I've had issues at Home Depot as well... lots of; "The computer says there are 2 in stock... I have no idea where they are."