One Card — Without notice and approval amount deducted

Hello,

Recently, one card has deducted amount in the name of Amazon prime, and best of my knowledge i have not set any auto debit anywhere. I am currently living outside India and I mailed them many time but no single revert I received from their end. I provided them transaction Id to track the amount and refund the amount but not a single mail is done by them in this regard. The amount is Rs. 463. I don't understand how without approval they can deduct the amount from someone's account.