Well a lot of breeders are counting on the fact that you get attached to a pup and won't want to give them back or trade for another. Anyway, if you were to get another, chances are high they will have the same condition(s), bc they are from the same breeding stock. Unless you actually post your certificate/guarantee whatever you got, I don't know what if anything you can do. If you get a few opinions from different vets and specialists and they all say surgery, then you definitely need to let your breeder know about, and they should foot the bill up to the purchase price of the pup. Who knows if they will even give you a penny, bc what they SHOULD have done is never breed dogs who had this condition to begin with.
Anyway, I get my supplements from
http://www.entirelypets.com I get the Cosequin brand. It's worked well for us, but then again surgery was not suggested for Uni. There are a few on here who have had the surgery. Recovery time is tough. At least 8 weeks bed rest. Just search "LP surgery" in the search box.
I strongly advise you go get a 2nd and 3rd opinion from board certified ortho specialist if possible.
On another note, Im quite surprised I am the only one responding. Is everyone else actually working?