Do you have salary relationship with HDFC? Then you can talk to your RM for upgrade, they will easily give you Millenia. Else, take the delivery but don't activate the card. Call the customer care and tell them your concern, mostly they won't do anything, after that you raise closure request, you may get call from retention team, they are the ones who can upgrade your card, they might ask salary slips or ITR as proofs for upgrade.
Moneyback is useless card unless you just want some credit card to get interest free credit period.