Adani Power Maharashtra Limited - Incorrect Recovery From Adani Power

I have received electricity bill from my current provider Tata which has dues from Adani (formerly Reliance) which is more than ** years ago. These dues as per the information provided by customer support is that it is the due when service provider was switched from Reliance to Tata. The bill is in name of my late father who passed away in ****. I have sent emails to Adani explaining the situation that we never received any bill about due amount also we have not received any reminder or recovery notice or any notification informing us about dues. We are still ready to settle the actual amount which is **** but they are not responding and asking us to pay ***** by adding interest every month. I have even received disconnection notice from my current service provider Tata because of these dues. This is really not fair how could they expect us to make payment for dues unless we are notified about dues or reminders or notice just like how it is done now.