Etihad Airways complaint: Miscommunication about allowed luggage and no services provided during 21 hours airport stay

As mentioned in subject, I travelled from Karachi to Manchester through Etihad airline on 26th May 2023 .Plz note following things which need to be compensated
1- I was told through email (dated 22 May) that , only 20 Kg of luggage is allowed and whereas at the time of boarding it was informed to me that I could carry 30 Kg. Due to this miscommunication I had to leave my important belongings at home in Karachi, which is costing me a lot in the UK as I have to buy things here.
2- Which is also a major reason for complaining is , during my 21 hours stay I was neither given room/food nor on arrival VISA due to which I had to face this inhuman behavior and stay at the seat of Abu Dhabi airport for more than a day.
in-spite of asking the transfer desk at Abu Dhabi airport , no one helped me in this regard which was a surprising and unexpected response for me from an airline of international repute like Etihad.
It is requested of you to look into this matter and compensate me for this non professional treatment
my contact details are 0044746636428