Non-functional charger cable under warranty

have you read Legal - Hardware Warranties - Apple

and maybe reached out to their service?

Get Support (apple.com)

And or

Contact - Official Apple Support

And or

Contact - How to Contact Us - Apple

Or

Genius Bar Reservation and Apple

Support Options - Apple

Return the cable to the retailer from which it was purchased. If purchased directly from Apple, you might consider visiting the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - who may be able to assist:

Genius Bar Reservation and Apple Support Options - Apple

This is a user-to-user technical community. Contributors here are all end-users, just like you. Other than directing you to appropriate resources, we can do nothing to assist with your warranty claim.

Other than the site Moderators, Apple neither monitors nor participates within this Community. As such, your comments here will not be seen by Apple Support.