If your payment is failing multiple times, it could be due to the following reasons:
1. If you are attempting to pay by a Debit card for the monthly membership, you would see an error that states that "recurring payments are not supported". Since the monthly membership is auto-renewed, you cannot pay using a debit card. You can pay using Zerodha funds or by Credit Card. Debit card is supported for all other plans except the monthly subscription.
2. If you are trying to pay using a foreign (non-Indian) card, the payment will not go through as international payments are not supported as of now.