Uber India — post-trip fare higher than fare asked after booking

Address:

Gurgaon, Haryana, 122002

I booked and wrote an uber bike this morning. From guru dronacharya metro station to v-12/19, dlf-iii, gurgaon, haryana. When i booked it the fare was showing rs.14 something; after we reached the destination, the fare changed to rs.28 something. I had paid rs 20/- to the driver thinking that i happily tipped him rs.5 over & above the asked fare. But as i was leaving the driver called me back and told me that the fare had changed. This is totally unfair. The fare should not change after booking. The amount is not much but what puts me off is that i booked for 'x' amount & i was charged 'x+y' after riding. Dear uber this is wrong