For Avaz Android app purchases via Google Play Store:
Please note that currently Net banking and Google Pay do not support purchase of subscriptions.
Click here to see - Accepted payment methods from Google Play
If you face problems for purchasing Avaz India app through online payment, read this link to see if it helps - Click here to see Google Wallet support for Indian Credit/ debit cards - For using Debit or Credit cards in India
If you still face problems, it might be best to begin troubleshooting with a Google Play Agent. Submit this form and an agent will call you back to help investigate further.