Uber Driver stole my phone

On the evening of 26 November I booked an Uber ride with Fekson Mutapati car registration CAA226812. On pick up he nearly drove off leaving one passenger behind who was just opening the door to get in which could have resulted in a serious injury. On drop off I left my cell phone in his car, I acknowledge it was my my mistake yes, however I contacted Feckson via the app, and he told me he would finish his current ride and return the phone This never happened. Instead I tracked my phone at various locations on find my iphone, and when I became suspicious and realised he had no intention of returning my phone, tried contacting him to have him disconnect my calls on numerous times. This is outright “ THEFT”. I contacted Uber who said they would contact the driver, and after not hearing back contacted them to have the same thing happen again and again, no follow up or communication. The last message I had was that they were going to escalate the matter and get back to me. That was on the 27 November, 8 days ago and I have had no communication from them. They seem completely disinterested and uncaring that one of their drivers representing their brand brazenly stole my phone without any consequence. and that anybody else who takes a ride with this same driver risk having the same thing happen should they end up in a similar situation as me.