Who should I contact for replacement of an iPhone case bought on Amazon?

Good afternoon,

I purchased an iPhone 16 Pro Max Ultramarine on the 02nd March. The case is already starting to tear in the corners and around the charging port. I have the same case in Stone Grey and Lake Green - both older and haven't peeled. The case was purchased from Apple via Amazon. Do I contact Amazon customer service with regards to a replacement under warranty, or Apple?

Thank you.

[Re-Titled by Moderator]

Original Title: iPhone 16 Pro Max Case Repair