Unfortunately, only the public choosing not buying puppy mill dogs will put them completely out of business. They are regulated under "agriculture" in most states that allow them, and as long as they "sort of" comply with livestock standards of cleanliness (which is low), population density (which is high) and care of the animals, they are completely within the law. That does NOT mean that this is how animals destined to be pets should be raised.
As far as your puppy being quite sociable, that happens too. Dogs that are hard to handle tend to get weeded out of the gene pool in puppy mills because they are, well, hard to handle. You are lucky you got such a delightful little guy from such a source. For future reference, it would be EXTREMELY unlikely to find a quality puppy from a reputable breeder being re-homed on FB, Craig's List, or other places of that sort. All reputable breeders have it written into their contract that the puppy or dog must be returned them if the owner finds that they can't or don't want to keep them anymore. And all quality Havanese puppies are AKC registered. (the converse is not always the case... it's entirely possible to find poor quality puppies with AKC registration)
There is really nothing you can do for the parents of your puppy... especially to without just adding to the problem by trying to buy them. Enjoy him for who he is, and consider this a learning experience.
Next time, you will know to find a reputable breeder when you want to buy a puppy, or will adopt from a REPUTABLE shelter or rescue. (those aren't all so good either!) And in the mean time, you can help other people avoid making the mistake you did, by guiding them into good decision when they are looking for a puppy!