Phone west missing

I used Uber to go home. I got the driver by the name of Siyanda. When i left the car i realized that i have left my phone on the seat i was seated on. I tried stopping the driver he just drove away faster. In 2minutes when i got to my house my phone was off. Now who took the phone? The driver is denying all this now. He did not even end the trip and i never rated him. <br> <br> What happens now? <br> <br> Is Uber going to help me investigate this more or i must take this matter forward to the police?