Fish Woes - 2,3,4..

Uaaaaannnn........ :(((
am jus left with 1 now...

4 have gone one after the other.. and I do not know why.
Ok, when the first one died, I took it to the shop owner, from where I bought them, to ask him and understand what actually went wrong.. so as to prevent anything wrong that may happen to the others. I was really scared.
Now this is what the guy said - "Madam, fish hai.. bolegi thodi ki kya problem hai .. kuch hoga, marr gayi.. fish to marti rehti hai.. abhi theek hoti hai abhi marr jaati hai.. kuch nai pata inka"... HUH !!! so this is what an expert has to say.. a guy who has been spending atleast 16 hours everyday with them, feeding them, carin for them, and earning a livelihood out of it ! I was shocked ! I insisted I was genuinely interested in knowing the reason, since I was worried about the rest, but he just made me feel, I am making a mole out of a mountain... ek fish hi to mari hai .. aur yeh madam !!

Phew! Anyways I thought of buying another one to keep them still 4 in number. And now I had a new series of woes. This new fish, looked a lil bigger than the rest.. was very UNFRIENDLY and DOMINANANT ! The only thing that this fish did was to scare the other fishes - run after them and poke them, and then all they could do was hide wherever they could. I thought that may be a kind of play because initially I did see some retaliation too, but as days went by, I saw more of fear than playfulness, and one by one the fishes just perished. They showed no evident signs of sickness, maybe it was just plain stress/fear that killed them. I am not sure.

The unfriendly fish is the only one I have now.. it seems happy somehow - content and calm - all by itself. I am not sure if its healthy for it to be all by itself, since the fishes live in a school, and breed the best in a group, but I dont have the courage to get another one and see something happen to it.

I still wonder what has happened and what is happening - But I have decided to learn more about fishes before I buy any more.
Its just too hurtful, to see them go...