GoAir — Refund not issued inspite of several followups

My Mother was supposed to travel from Mumbai to Lucknow on the 12th of june. The airlines cancelled the flight in which she was supposed to travel and gave us an option to either take another flight or get a full refund.
We requested for a full refund on 11th June by calling the customer care around 4:45 pm.
due to some mismanagement from their end they did not cancel our flight and the next day we received a call that we were a no show.
We raised the concern with the airlines and they assured us that it was a mix up from their end and we will get the refund within 30ndays.
we have followed up with them multiple times but still no response or update on status.
Still not received any refund and on top of that they repeat the same statement everytime we call and also, do not give us any written communication on where the process is.
We have been harassed enough mentally and financially. looking for a solution to this