I lost my package by UPS

Hello!, I am a foreigner buying in the US, on Monday, January 16, UPS scheduled the shipment of my package that was a Magic Keyboard, which was never delivered despite the fact my friend's mother who was going to receive the order was in the house and UPS never knocked on the door or called her on his cell phone. UPS has placed as evidence that it was left at the front door but it was a residencia without a guard. I never found my order and I would like to know how to proceed with the issue.