Capital First — Unauthorised transaction/deduction from my account

₹99.00 was deducted from my savings account by Capital First / IDFC First on 23 December, 2021. This is an unauthorised transaction, neither was I notified nor do I know the reason for the deduction. It was an NACH transaction. I have attached the screenshot of the transaction from my statement below.

1. Please refund my money.
2. Please remove me from your payments systems so that this isn't repeated in the future.
3. Please let me know why this happened in the first place.

I have seen multiple consumers' complaints regarding the exact same issue from around same time. So this is not new, and I expect a quick resolution. Thank you.