I did not receive a confirmation SMS/email for a transaction I am charged for.

If your transaction is successful, you shall see your booking under the 'Purchase History' of your app. Don't forget to check your Whatsapp/SMS/Email for a booking confirmation before attempting another transaction. 

In case you do not see a booking, it means the transaction did not go through and you can make a fresh booking. Rest assured, the amount charged would be refunded to the payment source within a maximum of 15 working days.