These examples make me feel that the regulations against false advertising are either insufficient. The last time I checked, in most states the only thing protected against is a monetary loss due to making a purchase that (1) wouldn't have been made otherwise, (2) resulted from provably incorrect information, and (3) that a reasonable person would have also assumed to be true. Implying falsehoods about a product without actually stating them is allowed. Outright lying is allowed, if a "reasonable person" would notice that they were lying. Only the monetary aspect is covered, and not the waste of time caused by the lying, such as your fruitless trip to Target, or needing to sift through all the lies.
Heck, in some states a buyer can't even bring a lawsuit for false advertising, only a competitor can. Because when somebody has lied to me and wasted my time, money, or both, isn't the wronged party really the unrelated person who didn't get to take my money instead?
The old joke about the difference between a used car salesman and a computer salesman comes to mind. ("...the used car salesman actually knows when he is lying to you!")
I'm not sure what legal basis there could be for anti-incompetence laws for web stores, nor how easily they might be passed. It'd likely have to be federal law, in the U.S. (At the state level, there are some nice, simple laws about in-store goods where the shelf says "Price $X", the check-out scanner say "Price $Y", and $Y > $X...)
My approach is mostly to have a long memory, and loose tongue, about such things. And to mostly shop at places considerably more competent and expensive than Target or Walmart.
Heck, in some states a buyer can't even bring a lawsuit for false advertising, only a competitor can. Because when somebody has lied to me and wasted my time, money, or both, isn't the wronged party really the unrelated person who didn't get to take my money instead?