Big Paws Only Dog Forums

I just purchased a Rhodesian Ridgeback two weeks ago and took the pup to the vet yesterday for his next set of shots and check-up. The vet informed me that the pup has a umbilical hernia that requires surgery. I know I should inform the breeder but shouldn't of the breeder informed me about the umbilical hernia when I made the purchase? I didn't know what the bump on his belly was....I have also asked the breeder to send me a receipt for the purchase because I paid cash and she has refused to send me one. Any suggestions as to what I should do?