Air India — Misplaced baggage

Address:

Mumbai City, Maharashtra, 221010

I was travelling from varanasi to mumbai by flight ai696. Scheduled at 1900 hrs & reached mumbai at 2150 hrs. I don't know how but probably due to wrong tagging of my luggage it got exchanged to a wrong bag. Since i was having another flight to chennai which due to delay of ai696 was very hard to catch.
Anyhow i managed to catch the flight but after reaching home & opening the bag found that the wrong bag with correct tag was delivered to me. I tried complaining the lost baggage but was instructed to return the bag at chennai first. I would humbly request you to please first arrange transfer of my baggage then only i would be able to return the bag.
Please urgent. I am attaching the boarding passes & baggage slips in this email for your convenience.
Now air india people are confirming me that my baggage is there only but are asking me to courier the bag from chennai to mumbai as they are unable to get it collected at chennai airport & would hand me my bag only when i courier the bag to them. They didn't even told me the address for courier.
Can you please help as my mother's all clothes & articles are in the bag only.