Amazon India — Fake Calls and Looting of Money

I received a call from amazon India and they told me i had won a gift because of my intensive shopping in the past few days. I believed it because it is true that i have been shopping a lot. But they asked me to pay extra money time and again claiming me a refund. I was a fool to believe them the first time. '
The man claimed to be a dispatch manager in the head office of Bangalore named Vivek Srivastava. I checked everywhere for his profile and found none. His mobile number is [protected]. I am still unsure whether he is a genuine amazon employee or a fake scammer. He knew all my details that i have only submitted to AMAZON Account.
Kindly let me know asap. Another number that called regarding the same issue is [protected]. I really hope you can just let me know whether these phone numbers belong to your company or not.