MakeMyTrip India — date change is not possible

Address:

Mumbai City, Maharashtra, 400053

I've been trying to change a date on a booking for the last two days. Customer care online or over the phone are not helpful. They keep sending me links to the date change section on the booking. The date change facility on the app only goes up to a certain point and then reads an error message 'oops something went wrong' when new date selection is to be done. Please help.