First off, a little story relevant to the OP. Silk Milk (or some other brand of soy milk) explicitly had a satisfaction guarantee. They said it applied even if you drank it all. I’ve only used it once, and it was when I was genuinely not satisfied. I’d gotten the wrong one, and while it tasted food for a milkshake, it was too sweet for anything I wanted to use it for.
Upon doing so, I found out they had an explicit limit of two a year. I’ve always assumed any other product has the same thing. Or at least a clause allowing them to deny you if they think you are gaming the system.
Now to address the other topic this had descended into: the reason that it can be wrong to return an item is that you could be lying. That’s the issue here. Exploiting a satisfaction guaranteed policy can be lying because you keep on using it, indicating satisfaction, yet your return says you were not satisfied. Returning an item as broken after you’ve abused it is lying because nearly every broken return policy indicates the brokenness must not be your fault.
But a store that really has a “no questions asked” policy? Exploiting that is perfectly fine. It is exactly analogous to the lifetime warranty. They’ve told you up front that any return is acceptable. Yes, they may prefer you not to return an abused item, but you are under no obligation to go with their preference, any more than you’d have to listen to my preference if I say I’d prefer you not to post.