How did you manage that because Apple will not replace under warranty or Apple Care a laptop replacement or part for free if it is considered to have been damaged by the customer.
This is not always true in-store. I've seen this first-hand on multiple occasions with iPhone screens, and even my own iPad (SIM slot damage). But the most prominent case was a friend having their ~£3,500 water-damaged MBP replaced completely free. Similar to the OP, it was only a few days old. He was completely honest with what happened - the Apple employee disappeared for a bit, then came back and ordered a replacement, putting his through as 'DOA'.
Always go into a store with these issues and just be honest.
Best of luck OP - it goes without saying, be extra careful with that Mac now it's had its warranty void.