Icici late payment fee and interest

No chance for any refund of late payment fee.. better pay else it will keep rising 

Pay the full bill. Ask the customer care for some concession stating that this is your first time mistake

since many days have passed, your reversal is tough to come but if it's your first mistake then try asking them. meanwhile make the full payment if not made already

Clear all the outstanding first, then fight with them for charges.

The OP's mistake is exactly why I enable auto-debit for the full amount on all my credit cards. I always pay my credit cards a week before they are due and thus the auto-debit never kicks in.

I did this after I mistakenly made a partial payment (a couple of thousand rupees short on full dues of over 2 lakhs) and was charged an eye-watering interest amount on the full dues. I requested the customer care to reverse it as it was a first time mistake. He did reverse it to the maximum limit he was allowed to. He suggested to enable auto-debit to avoid this in future.