Air India — Refund for ticket cancellation

I had booked a flight for self and my son from Kolkata to Mumbai on 30 Aug.(PNR: LNYD6M Tkt nos: 098 [protected] & 098 [protected]). However due to change of plan I called the customer care on 28 Aug to cancel my tkt. However I was suggested by the agent that I should make it an open tkt rather than cancelling it. In that way I can use the tkt anytime in the same sector within a year or if I decide to cancel the tkt before 1 year I will get the refund which was due to me on that day ie 28 Aug 23. I asked her if I'll get any confirmation mail regarding it but was told no it will be in the system and I just need to call and give the PNR reference. In Dec 23 when I called the customer care to use the tkt I was told that no such provision exists. I was really shocked to hear this and sent a query immediately but haven't received any response. kindly look into the matter and resolve at the earliest. Thanks Rashmi Jha(FF no[protected] Mob [protected]/ [protected]