Package Delivered but Customer cannot find it?

Okay so a customer reached out last night and said that the package says delivered but he cannot find the package. I looked up the tracking number and it says “Your item has been delivered to an agent and left with an individual at the address at 11:47 am on March 23, 2025 in MIAMI, FL 33166.”. The buyer messaged me 7 days after it was delivered claiming that they never received it and USPS has not responded to them. When I looked up the address it links it to a wearhouse with a business. I kindly responded providing all of the tracking information and mentioned that if it was delivered to a business that he as any employees if they have received a package.

What will happen if they do not find the package? Will I be forced to refund them there money? This is the first time I have come across this issue.