Hey, I'm paying multiple electricity bills total around Rs.12,000 every month. Can anyone suggest a way to gain maximum cashback for this.(I own Airtel Axis CC, HDFC Moneyback DC, SBI Platinum DC)? Wondering if i should apply for HDFC Millenia debit card (to use in Smartbuy) or SBI Cashback CC or Amazon ICICI CC. Please suggest which would be best.