Ola Cabs — Cancelled at last Moment but its book a day before with confirmed status

As I booked Ola its booked with conformed status yesterday 7/8/2015. But at last moment its has been cancelled by driver if I have some urgent thing than I booked Ola. If this kind of response give by Ola than what kind of trust can be built on others person. My father having booking in train that time if he miss the train who will pay Ola. Ola saying sorry for Inconvenient at last moment if he say straight before that we can not provide the Cab than we can try some other ways but its not at all acceptable for this case. This is very ridicules response by customer support too