It is very true, for a store, a garment that goes out without invoicing does not affect their sales volume. And just as you say, the employee can be harmed. I wouldn't return the garment either.
In addition, I would take it as a payment for everything I have bought that has turned out to be of poor quality, garments that I have only been able to wear a couple of times. Here it does not apply that of warranties.

I would be happier than a kid eating candy.