I bought a large koi from a reputable dealer in October. He kept it until last week when I picked it up on Friday along with another large koi. The asagi acted very lethargic and within a few days had fin rot. Per the dealer's instruction, I put pp directly on the fins on Wednesday. This morning he told me to do an antibiotic injection. By the time I got home with the Baytril, the fish was dead, exactly one week after I got him. The other fish is fine.
Is it proper to ask for a replacement? The fish was several hundred dollars, and was the most expensive I ever purchased. All the koi in the pond are from this same dealer, so he's had plenty of business from me over the years.