Heart Murmure in new puppy?

You bought from a bad breeder. Sad to say but you most likely will not get any of your money back. Just cherish the puppy you have now. Heart murmurs can go away in puppies, so don't give up hope. Also, with treatment your dog may live a full life without much problem. A good breeder would have a health guarantee, but from the looks of it, this breeder doesn't do much of anything but breed dogs for money. I'm sorry to hear about that but consider it a hard lesson learned. I've been through a similar case, all you can do is love your dog and next time pay the extra money from a reputable breeder. Bad breeders are good at convincing you to buy from them, that's how they make money. Unless the breeder wants to stay in contact, has a health guarantee, and you pay a down payment for the puppy, then stay clear, because most likely it is a BYB who doesn't care about the health of the puppies they produce.