Indigo Airlines — Payment declined

I am Sanjana. Since yesterday (07.08.23) I have been trying to book a return flight from Goa to Kolkata. But every time I am entering the card details it is showing payment declined by bank, which worked perfectly fine for the last booking done a few minutes back for flight from Kolkata to Goa. I tried using another card but got the same response. Today I contacted the bank and they said they have no issue from their end. I would request you to kindly look into the matter.