Xiaomi India — Not refunded discount as per scheme

I have purchased 40 inch mi tv from offline mi store m/s. Mobile mart (Parimal), bhavnagar, gujarat on 27/10/2019 vide invoice no. Gst-p-01608 and arrange the payment through HDFC debit card.
As per the scheme Rs. 1800/- requires to refund though payment made through HDFC. More than one and half year passed, but refund of Rs. 1800/- yet to received.
you are requested to please check your data and arrange the payment at the earliest.