Air India — No show rules in customer care

Hi,
I have booked a ticket for 3 persons in December 2022 from Copenhagen to Kolkata via Delhi. One of the passengers had to go to India on an emergency medical ground and is still in India. As per the ticket we were supposed to travel on 9th June and back on 30th July. I called Air India customer care when Air India resumed flight again between Copenhagen and India and I was told that I have to pay a no-show charge in Copenhagen airport so that the passenger who is in India can avail the sectors. Today when I called back, to know the baggage regulation sin this case, I was told by the customer care personnel, that this is not allowed. And I was told to cancel the ticket for the eprson and book the ticket from Kolkata to Copenhagen separately. Due to the misinformation at the first place I had made plans where that passenger can join in the Delhi-Kolkata sector and now I have to pay enormous amount for return back to Copenhagen one way, book a separate ticket from Delhi to Kolkata, pay the cancellation charges. In effect a harrasment due to misinformation which could have been solved months back.