Air India Airlines - Luggage not delivered and mental stress

I am writing this complaint to inform you that I had encountered the worst travelling experience ever in my life on Air India recently. I was one of the passengers on AI ***, seat numbers **A(my partner) and **B(myself) who travelled from London Heathrow to cochi via New Delhi on the *th of April .

* We booked Air India's direct flight tickets from LHR to COK, but within one week Air India have changed the status to a connection flight with ** hours delay at Delhi airport without prior notification. We came to know only after we contacted the Air lines just a few before the actual flying date.This was unexpected and we wasted ** hours at Delhi Airport with lots of stress and expenses, that leads my partner to become unwell and needed to book a room in holiday Inn by paying £***.

* We had to do our Covid_** test at Delhi Airport to get the negative result prior to reach India as we are international travellers, where we couldn't see any of the Covid_** protection protocols as none of your staff members following social distancing and the staff with same PPE doing all the Covid Swabs which is unhygienic and easy to spread infection, also the passengers were wandering with no restrictions and security staff were chatting within themselves without following any Covid_** guidelines. Moreover, we had to pay RS:****/ for RT-PCR test and lounge(which is understandable),however the standard was pathetic arranged with normal chair instead of a proper comfortable lounge chair that lead to backpack for myself. It's hard to believe that The Indria Gandhi Airport authorities charge RS:**** for those kind of waiting area.Is that for we paid Rs. **** each which is too much compared to every other testing centres?
* After getting the result, one of Delhi airport members asked us to follow him without giving any information ,once we reached a counter only realised that it was for getting boarding passess to Kochin flight which was at **.** on *th April ****. We been told clearly that baggages will be transferred to our connecting flight to Kochi without any delay.

*Waited then at Delhi Airport from early morning **.** am till evening **.** to get the connection flight to cochi which made us physically and mentally unwell. Before the departure when we checked with the airport authorities about baggage the ground staff mentioned its been transferred. However, the Important thing is once we reached at cochi airport only realised that our luggage still stuck at Delhi and will take another * days to deliver it. All these issues happened because of lack of communication to your passengers and this is so embarrassing because I'm still waiting for my luggage. I am not sure everything inside my luggage is still intact or damaged.
For all these reasons, we would like to let you know that we are legally eligible for compensation and put complaint against services provided by Air India in court. I am writing this complaint on **th April **** at **.** whilst still waiting for my luggage to be delivered which contain my valuables and medications.
One more thing to add when I contacted the Air India staff in Delhi Airport and cochin the staffs(not mentioning their names now) were so rude instead of reassuring and giving an solution.

Unfortunately, our return flight is also booked with Air India from cochin to London Heathrow via direct flight, for which we expect a better experience. I hope I get updated in advance if there is any amendments with the flight.

Thank you