I think I would have bypassed whatever phone number they may have left for you on your voice mail and just called 1K reservations where you could have avoided talking to the India call center in the first place.

I don't understand why you got a phone call at all.. I've never had such a message before. Perhaps someone was auditing this sponsorship and was suspicious for some reason. But good luck finding out.. I fear you'll be sent into an abyss of non-information.