How can I optimize cashback on electricity bill payment?

I used to pay my electricity bill in advance from amazon pay using my cc and get some cashback and then pay the remaining amount from airtel thanks using airtel axis cc and get the 10% cashback (as my electricity supplier doesn't have half payment option once bill is generated).

Now, I see that amazon pay has removed advanced bill pay option. Where else can I pay advance bill from to save some money via cashback?