Connection problem

New Apple Watches ship with watchOS 6 and require an iPhone 6s, SE, 7 or newer running iOS 13

Apple Holiday Return Policy (Purchase between: 15-Nov-2019 thru 25-Dec-2019, Return by 8-Jan-2020)

All purchases made before November 15, 2019 and after December 25, 2019, are subject to the Standard 14-day Return Policy. 

https://www.apple.com/shop/help/returns_refund

Does the apple watch 3 have watchos6 on it?, if so that is why it won't pair,watchos6 requires a phone with at least ios 13 or higher.