Uber India — Overcharging on ride

Address:	400004
Website:	Uber App

On friday 23rd june'17 i travelled by uber from malad to charni road. When i booked the cab, the upfront fare shown was rs. 504.43, while at the end of the ride an amount of rs. 845.88 was charged to me.
When i raised a query with uber, they confirmed that the fare which was shown was indeed rs. 504.43 and due to high demand the fare was increased and and deducted at the end of the trip and that they will not refund the difference amount.
If they intend to deduct a different amount than what is shown initially what is the point of showing the amount at all.