Of course I wouldn't take the puppy back to be resold to anyone with money in their pockets, or to end up dumped at a shelter because it's shelf life has expired and it's not profitable anymore.
But, in your case, this is how petstores sell puppies. Many people cannot/won't wait for a puppy from a reputable breeder or rescue and want what they want right now. You can see how it happens. Your husband KNEW all about the abuse and mills, yet got one there anyway. Many people do not know.
What you can do is spread the word about where petstore puppies come from and urge everyone you know NOT to patronize these stores at all and to tell the store WHY they will not shop there. Petstores care only about profit/loss, so the only way to put pressure on them is to cut their profits.
You could also volunteer to help a rescue. There are many ways to do this, incuding fostering animals, helping at adoption events or fundraisers etc and your help would be so appreciated!!