Go Airlines — Fraud in advertising

I had booked a ticket with go air in their web site on 10.03.20 as per the following advertisement by go air wherein go was offering free cancellation, even as the charges where very high compared to indigo my favorite airline and spice.

Howver on 12.03.20 they have issued a new advertisement saying only free rescheduling applicable.

My pnr bi is y1lhre and while trying to cancel i am finding that the cancellation fees are being charged.

I am not in a position to travel on 8th june and i want to cancel and get a full refund as shown in the advertisement.

This is fraud by the go airlines company
I have wrote to them vide email on 13-03-20 and again on 16-03-20 wherein i got a confirmation that they received the mail however till date no further response.

Please assist me to get a cancellation refund from go airways