GoAir — Rescheduling of previous booked ticket

I have a booked goair ticket on dated 15/03/2020 and pnr no/booking reference t3khjl allotted to me for travelling. Due to nationwide lockdown i couldnot performed my journey on 06/05/2020 fm jammu to patna. Now, i want to reschedule my trip from your wbsite but i am unable to do so. An error is occurred while rescheduling my flight on dtd 23/10/2020 as i want travel on the date from and to the same destination as i booked earlier. Kindly look into the matter and resolve the problem at earliest so that i can take n/a. I also want to say that the custoter care centre of goair is not responding to call.