Permissible and impermissible items of trade

Purchasing a TV on interest

Q: I bought a TV with option of no cost emi of 3 months. After emi completion, Later I found out that it is not permissible and it involves interest as bank gives loan and charges interest and then I checked my statement and found out.

I usually buy items paying all amount but this happened first time that I had to take this option of no cost emi. From the day, I came to know I am feeling bad. Should I sell of my TV or keep it? If I sell I won't even get 50% of amount which I took. So I am in a dilema. What should I do in this case.

Selling cigarettes

Q: I live with my grandparents and they have a shop which sell mostly biscuits & they also sell cigarattes! (According to some sholars in my country cigrattes are makrooh, while I have heard some Arab scholars say its haraam).

I want to be on the safe side so, as I live in their house my concern is I use electricity/internet to learn as I learn online! Will my online earning be halal if I pay them later on for electricity/internet I use?