Individual — Galaxy s21 black screen

Website:

Amazon/Integron

I was presented with a new Samsung s21+ that cost approximately USD900.00 for my birthday in April 2021 and by June the screen went black.
The phone was bought on Amazon and neither Amazon nor the seller Integron have taken responsibility for the phone that lasted 8 weeks.
Since then I have been unable to get the phone issue resolved so I shipped it to Samsung in the US last week who say the phone is an international phone and that the warranty does not apply in the US.
How can this issue be resolved without further cost to me?

Regards