Uber India — driver won't return a lost item

Address:	Kolkata, West Bengal, 700075
Website:	Uber.com

I took a trip on 9th July and left my umbrella. An hour later I called the driver. He said he has my umbrella but refused to meet somewhere to return it. It is Wednesday today and I still haven't got it back. Everytime I call him he says he will drop it when he comes round this neighborhood. But he never gives a time frame. I have received no phone calls from him about when he will give it back. I am leaving town tomorrow night. I need it back urgently. Please please help me.