Closing old dormant demat account - Ridiculous AMC charges

I had a demat account opened long time back and it has been dormant (no activity) since past 9 years. I tried closing it recently through broker app but my closure request was rejected and they told to contact their customer care. When I contacted customer care, they said my closure request was rejected due to past AMC dues. They were charging AMC every year on my dormant demat account resulting in total unpaid dues of around 3000. Do I need to pay such ridiculous AMC fees for closing the accoint or is there any possibility to get the fees waived off?