If the transaction through Wallet has failed at the end of the ride, please ask your driver to check his app at the end of the ride. If it shows paid online, then you can clear your remaining dues later on your app. In this case do not pay the driver partner through any mode of payment separately but only through the Ola app.
If it displays a specific amount to be paid in Cash then please pay the required amount to the Driver.
If the transaction failed during clearing of your outstanding dues, then please select any other available payment method to clear the dues.