What will happen if any bank charges wrongful Demat account maintenan

Respected Sir/Madam, In 2019, I requested ICICI Securities to close my Demat account. I received an email confirming the trading account was closed but heard nothing about the Demat account. I assumed it was also closed. Recently, in April 2024, I learned my Demat account was still active and I had been charged ₹826/year since 2019. I filed a complaint on the SEBI SCORES portal. ICICI Securities claimed my trading account was closed in 2019 but the Demat account was only closed in April 2024. Despite this, they provided conflicting responses, saying both accounts were closed in January 2019. I escalated to NSDL and ICICI Bank but got redirected without resolution. I seek your guidance on how to proceed for a refund of these charges. Regards, Vishwanath