Stole my phone in less than 15 minutes

I returned the rental car to the Las Vegas airport and left my cell phone in the cup holder.  I realized I left it just as soon as the shuttle bus pulled off to go to the airport.  Using another phone I immediately called Enterprise to retrieve my phone and let them know I was on my way back to pick up the phone.  When I got back to where I dropped off the car, they stated they could not find my phone.  Joe, the person who checked me in, reviewed and recorded my mileage and gas tank had just left for lunch.  

How could my phone be lost in less than 15 minutes?  They stole my phone.  It must be the culture of Enterprise because they did not seem to care.  They just said, "We couldn't find it".... "Can I help the next person in line" was the attitude.   So much for "We go the extra mile".  Instead they are just enterprising thieves.