Mega Cabs — overcharging by driver

I travelled from t3 to shangri-la in megacab the sms receipt i got said the charge is rs 397 and the driver took rs 600 on the ground that he is not able to log on. He gave me a hand written receipt. Attached are both receipts. I also called the customer care but they told me to pay the driver and register complaint. Please refund the additional amount.
Anupam dighe