New phone with useless battery won't be replaced

I got a brand new S22 as an upgrade. It's battery is at 50percent within 2hours, clearly has a problem. Now you guys won't give me a new device after technicians said "there's nothing wrong" when clearly there is. Now I have to pay you for 2 years for a phone that doesn't work. As a customer with 3 contracts with you, loyal for more than 10 years, this is a massive F you to me the customer. Definitely moving all my contracts when their time is up.