ICICI Bank Ltd — Demat account charge deducted without any demat account

Dear sir,

I have a saving account no[protected] with icici bank.
Recently on 27 August INR 826.00 was deducted from my account against DMC/IN[protected] DP CHGS TILL July -2021. I couldn't know why this charges have been deducted. I have Googled it and I came to know that it is probably charge for using Demat account. If it is so, then I want to bring you in the notice that I never had any Demat account in icici and even I don't know what is Demat account and how to use it.
I am surprise to know that bank has deducted the charges for something that doesn't even exist

I request you to kindly look into it and refund my money as soon as possible. Also kindly arrange to stop these arbitrary action of bank.