Your way of asking them to give you information & you confirming is equally harmful. A scam running right now in India is when a customer gets a credit card fr

Your way of asking them to give you information & you confirming is equally harmful. A scam running right now in India is when a customer gets a credit card from SBI Bank, somebody in the system sells this info (that they have got a SBI Credit card) & Name + Phone number. Few days later, customer gets a first call that We are calling from Rewards section of SBI, you are entitled for 20% discount card, we will not ask you credit card info, just confirm if you have SBI card? Customer said Yes? Scammers update their database. Few more days, again somebody calls, says You HAVE card from SBI, for rewards, just confirm if it is Visa or MasterCard? Some other time they don't even ask, they insist you HAVE Visa, if you says Yes, they benefit, if you say No, they say sorry, mistake in our system, we will correct it. They still got what they wanted. The moral is they build up the card info one bit at a time. The only way to tackle is to deny you have any card on every call you get as officially Bank never calls you for rewards.