Utility bill payments advice

Hi,

Want some advice on utility bill payments (using auto debit or standing instruction) using credit cards for best rewards or points or discounts.

1. Electricity bill CESC – 5500 per month
2. Airtel broadband bill – 1300 per month
3. Multiple Airtel postpaid – 600 per month

I have Standard Chartered value, SBI simply click, Kotak Royale, Citibank cashback, HSBC & ICICI credit cards. Out of these I mostly use Kotak and SCB and am not getting optimum reward points. I don’t have SI or ECS setup.

Please advise, thanks