Amazon India — No Customer Service - Fraud action to promote Amazon Card

My 2 visa cards works everywhere in USA and India. But since 3rd week of March 2021, stop working in Amazon India.
Both banks related the cards cannot see the payment request coming from Amazon India.
Now from here things get tricky. In amazon site you cannot find straight forward way to find customer service number. it will be hour of wild goose chasing. Then I discover they only call back local Indian number, No global number provided.
Since last 2 months I see the amazon card promotion increased and finally without any reason other cards stop working.
Yet to hear anything fruitful regarding email complain.
They will keep sending messages like check the card number, expiry date and all other useless messages.