Uber India — the driver collected extra money than shown in uber application

Address:	500009
Website:	www.uber.com

It's[protected], i took ride from secunderabad station to sikh village, the price shown in app was 210 but after applying coupon which uber sent me in mail, it was 160 rupees.
When i arrived my destination, the driver said it's 210, i shown him the price in app also the latest uber receipt which i received immediately.
He refused the app price and also the uber receipt.
He said, it's may be the application fault.
And after an argument of 10 minute's, i handed him 210 rupees and he left.
He took extra 50 from me saying that the uber application is having faulty receipt.
What should i do now.
This was not my first ride uber, i already did dozens of rides in hyderabad.
But this time, with a bad experience of this.
Should be corrected.
And i need my 50 rupees return.
Thanks.