This happens if you purchased any SIP or basket by providing one time mandate.
The amount gets debited for the purchase of SIP units or smallcase basket as per the date and frequency opted by you.
Why are my unused funds credited back to my trading account?
What are the adjustments involved in the calculation of my withdrawable balance?
How do I change my payout settlement cycle?
What will happen to the amount lying in my trading account if I close my trading account?