Sub-letting premises and non payment to landlord

I was living in a sharing accommodation not having any link with the main owner. There is a 3rd person who took from the main owner and rent to 4-5 people. We were paying that person timely.

But maybe he did not pay to the main owner, and suddenly main owner representative came and give all 4-5 people notice to pay 8 months' due rent, which we already paid to that agent in cash.

We told him we don't know you and neither we have any agreement better to catch that 3rd person whom you have an agreement with. One day, the owner came to the flat and took out Emirates ID copy.

Anyhow, we vacated the room already and now he is calling on the phone and asking us to pay electricity bills. We told him we already paid to the 3rd person. He said he will take legal action.

Kindly advise what can happen. We paid all the rent which is including everything. We are salaried persons and we are afraid.