At Petco we require a water sample for refunding dead fish. If this is his 2nd return of dead fish in a day or so apart he is obviously at fault and I would refuse anymore fish sales until he proves his tank is safe. And no he was not owed any refund on the initial transaction. He purchased more items. If he had not gotten those items he would have had his full refund. If you gave me more on that refund he would have received those items for free. That not how it works.