ICICI bank credit card offer applied on Amazon Pay credit card

Purchased Sony MDR-XB50BSRZE Bluetooth Earphones (Red) https://ddime.i...71 from Croma was trying to buy Croma 1K GV from SmartBuy through HDFC Millenia DC for 10% CB but failed due to checkout error at the end, coz the deal is tempting decided to checkout without discount, then also for a try clicked offer apply button ICICI bank credit card 5% instant discount which was popping and what a pleasant surprise offer applied so thought of creating this thread to inform and also to know is there more sites where this combination working

Will also appreciate if anyone could tell me why purchasing Croma voucher failed I have bought 5K Amazon voucher this month due to limitation