Why is everyone coming to Napa's defense?
Likely because they don't have problems with NAPA. Witness another poster's comment that one unhappy customer can lead to the loss of more. Human nature is to listen to people you have reason to trust (friends, family) and then trust their statements, especially if you have no evidence to the contrary.
Most of us do this - new restaurant in town, never been there, a friend or family member tells me they went and that the food/service is horrible. Guess what very likely no longer remains at the top of my list?
A corollary to the "one unhappy customer leads to loss of more" is how we react to positive and negative situations. Retail organizations have gathered statistics on how, when presented with an overwhelmingly positive customer service situation or an overwhelmingly negative customer situation, those involved are far, far more likely to tell multiple people about the negative situation, whereas those with the positive experience will, if telling anyone, likely only tell one or two people. It's all about the emotional response generated - we human beings anger more easily than we are pleased, and calm far less rapidly.
In the "real world", it's increasingly UNCOMMON for one to relate the fantastic customer service experiences that they have.
This forum is a very different community than the "real world" one we live in, in the sense that members here DO regularly report positive experiences, and when a scathing review comes in on an organization or establishment that we personally have experience with, a review in stark opposition to our own experiences, we're compelled to provide that information (much like other members with negative experiences feel compelled to provide their information).
This especially extends to chain/franchise organizations. In this case, we're dealing with NAPA. NAPA has over 6100 stores. Many/most of those are franchise operations. The OP had an issue at ONE of those stores. I can personally attest that his experiences are in no way similar to my experiences at three different franchisees and two locations (comprising 12 stores in total). As we've seen, other people have had positive experiences as well.
We're a social group. We talk about things here, and this is what happens.
My hypothetical restaurant example above? Had I tried the restaurant prior to being given a negative review and had an experience to the contrary? I'd most certainly disagree with the person who was giving me the opposing viewpoint, based on my experience.
The industry standard is to allow returns for at least 30 days. A receipt is evidence of purchase, not a business agreement.
There's not really any kind of "industry standard". Except in the case of defective product, retail establishments are NOT required to accept returns. There's no law protecting one's desire to change their mind. *IF* an establishment accepts returns, 30 days is a common date, but it's by no means ubiquitous.
To the OP: Napa takes used oil right? Just drop off all used oil right on their countertop.
Yeeeaaaaah, advocating vandalism is incredibly mature. That's a perfectly rational response to disagreeing with a store policy (that is likely printed somewhere other than the receipt).