Phone ****** in Uber - NEVER trust your driver

On Saturday evening my fiance and I took an Uber. We were picked up at 11:11 and our ride ended at 11:47. During this trip, my phone was taken from me, presumably by the Uber Driver, as this was the only other person in the car. My "google find my phone" indicate that it was switched off at 11:29 - right in the middle of our Uber trip. This phone was on 70% battery life as this was the phone used to request the trip. This is unacceptable that my private property was taken by someone I pay for a service. It has been 2 days and Uber is not actively helping me in any way - I just get emails saying this has been escalated and they phoned me asking if I was physically harmed. I contacted the driver, who indicated that he did not know anything about my phone and can apparently barely remember us taking the Uber - very convenient. I want action to be taken against this guy - if he can steel phones, what else can he do to an Uber customer. Unacceptable!!