Deaf puppy

[msc1]

Hello, I've recently just taken home a 10 week old Cobberdog puppy and with 24 hours I've realised she is deaf. I was not notified of this before pick up and the breeder is claiming it wasn't picked up in the testing.  I've paid $5,750 for the puppy and the breeder is offering to refund half the money. While the puppy is very sweet, it seems alot to pay close to $3,000 for a deaf puppy. I was wondering if anyone else has been in a similar position? Or if there is any advice on if I keep her what a reasonable price to pay is? Thank you for your thoughts.