No, it would be adjusted in future "purchases" - but if no future purchases ever - I guess its a good question what they would do. Maybe if you try to cancel they may ask you to pay 😕
But yes EMI is the reason. Many cards have changed T&C in recent times to include EMI not eligible for cashback (apart from things like rent, wallet loads etc) - but till a transaction is converted to EMI - they are not able to identify, hence cashback may be given. I am in the same situation with my SBI card - which I dont use much, when I called to ask why my 183 rs cashback was not credited, thats what they told me that some 200+ negative is the cashback which will be adjusted with future purchases. Now, I dont use the card that much - so need to see.