Im an NRI and visit India quite often. I am one of the Million satisfied user of the American Express Card. It does not matter where you use it - the quality remains the same. I had bought a costly pair of sunglasses in the United States and I happened to crack its lens accidently. Through the 3 month extended warranty provided by Amex on all purchases, (services depend on which Amex card you use), I got a full refund check by mail once I called customer service and told them about the incident. This was in the United States and things in India - in such matters - might be a little different. They might want to verify of what you are saying is the truth. However in India, VISA and Mastercard are the ones used more commonly and there would be companies such as CitiBank providing similiar services.
I am a satisfied customer of Amex and I would recommend it to anybody shopping for a Credit Card.