If you have made a booking, you should have received a copy of the receipt with the payment details at the email address you entered during booking. Do check your spam folder, and if you still don't see your receipt, but the amount is debited from your bank account, you can print or email it to yourself by accessing your booking record using the confirmation number displayed in the confirmation page through ‘Manage my Booking’ 

Please contact Tata Neu Customer Care for any assistance.