Always here to help!
Please check if the correct details are entered like the expiration date, CVV,VBV/MSC password, etc.
Still, no luck? We suggest you to try using an alternate payment option. 
If the issue persists, please connect with the respective bank/source.

Note - If you are trying to transact using international card, transaction may fail. We request you to try transacting using Indian bank-issued debit card/ credit card or pay using PayPal and you should be good to go.