Consumer Redressal

I booked a round trip flight ticket with MakeMyTrip Private Ltd. on 10th March 2020 of an amount of INR 67572 for a trip travel date on 24th July 2020 but on that very day they didn't send me the INVOICE for my concerned booking. Now as per the current scenario, the booking for both my flights that included in my booking with MakeMyTrip got cancelled from the airline end and they provided email confirmation after which I had to go through many hardships and struggles by writing to them over mail and social media. Finally, after 5 months of the struggle of my cancellation, they provided the FULL refund of my booking of an amount of INR 67572 on 4th September 2020 without any deduction. But now when I am asking them to provide me with the cancellation invoice they aren't responding over mails or twitter handles on my concerned raised in front of them. Basically, they didn't provide me with either of the invoices, 1st booking invoice and 2nd cancellation invoice.