I am really sorry you had such a bad experience... Maybe this will make you feel better: That specific petland is under new management, and the new owner is very responsible towards her customers, her breeders, and the dogs in general.
I bought an 8wk old boxer there who is now 8 months old, and happy and healthy. He's the love of my life, and they even put me in contact with the breeder (who is not from HUNTE as every misinformed ### on the internet thinks).
Every Petland is owned by a different person- these are franchises. Responsibility is ultimately on you, to ask for the breeder's information and papers. I learned the hard way, my first go round where I thought I bought a pure bred chihuahua, and ended up with a basenji/chihuahua mix.
Breeders can be JUST as deceiving as pet stores. Just make sure you're informed before you spend 2k on anything, not just dogs.