Petco complaint: Would not sell me the items I needed

Mgr , would not sell fish. He started asking all kinds of question . I told that my half my fish died from power outage. Then he said Petco will not sell fish because the water may be contaminated. I said I already bought a 35 gal tank with everything new. The fish that survived. Have been in the new tank for 5 days and they had babies. Still he refused to sell me fish. So I left on the way out I saw some clearance items . Picked a couple of items but when I went to check out the cashier refused to sell them to at the discounted price and rang them up at full price. And I walked out refused to pay the price she rang up as. Don’t understand I’ve been a Petco customer and have never been refused service. In fact the other store have been down home people going the extra mile to get what you came from. This is a store I do not frequent but I was on the home and need to get. Few things. I am still in shock and in my mind I wonder why the treated me that way.