MakeMyTrip India — 2X refund voucher is invalid

This is regarding the booking I’d-NR[protected]. Opted the option trip guarantee to book the train ticket. After the chart preparation the ticket got cancelled due to waiting list as per the policy of trip guarantee. The refund was initiated and I received it as well. The issue is about the 2X refund voucher which I received from make my trip. I tried using the voucher to book a train again but there comes a pop up that “sorry! Promocode used is not applicable at the moment”. Note- I read and understood the t&c of trip guarantee and tried with all the options to book a train with the voucher code but it doesn’t work!!