i too got a similar call but in relation with kotak bank where I don’t have any relationship…. Bluffed with them for couple of minutes not revealing even slightest of info… Infact tortured them saying you people have misleaded me on various occasions related annual fee/credit limit etc….. And insisted that i wouldn’t take anything new, & to get an agent to speak in kannada (my mother tounge) frustrated they disconnected the call
they also mentioned 4000 worth gift vouchers/ 8k worth travel vouchers