Ibibo Group / Goibibo — Flight booking for Dubai

We have booked a flight from Mumbai to Sharjah on 23 january and return via goibibo in Vistara airline but due to Corona restriction we were unable to travel on that date so Goibibo put the Ticket in open status and sent me a mail that we can book our flight any time and date within one year by giving the fare difference but now the customer support is refusing to book the flight saying the ticket