Air India — Charged for baggage lost

Address:

53,Ranmsomes way

I am an International student and I travelled from India to London on 13 sept 2021. Unfortunately someone else took my baggage and I by mistake I took the other person's luggage. After one day I went back all the way to the airport to get my luggage and they charged me 70 pounds for returning my luggage. I requested them but they refused to give me my luggage. At last I had to give them the money and take luggage back as I was all alone in UK.
I want my money back as it was not fair to charge me that money and I its a decent amount of money for me as I am a student.
PLEASE FIND THE DOCUMENTS ATTACHED BELOW.