Murder!

This is the culprit

About a month ago I got two fish. Now when I got them, I was sure to ask the pet store lady if they were aggressive or not, seeing as I don't know a heap about fish breeds. She told me that the two I had picked out should get along just fine, even though one was larger and the other smaller. I put both fish in a two gallon tank in my dorm room. Everything seemed to be going fine at first. But then! I noticed that the larger of the two, which was only an inch long, was a pig! He was always hungry and would get so excited at feeding time(I felt a spiritual connection with him because of this). The food I got them said to only feed three times a day and only as much as your fish could eat in two minutes. Well what the heck was I supposed to do when Fatty (the larger fish) would suck down huge amounts in under two minutes?! I just kept giving him more and he just kept eating it all. I know, I know, there is such a thing as overfeeding. The problem was, when I didn't feed him as much, he would go and chase Anex (the little one) around and nip at him. Anyways this was just how it was. A month went by until today and I decided it was time to clean the tank. After some struggle with both troublesome little fillets, I got them out and cleaned the tank. I only had one container to put them in, so I put both in there, not thinking twice about it. I leave them alone for 5 minutes to set up the tank and come back to a serious conundrum. Only one fish was in the container! *dun-dun-daaaaa* Now I seriously thought someone was punking me at first, and stole my fish. I soon came to accept that in such close quarters, Fatty had finally caught his prey and poor Anex hadn't stood a chance. So now I have one murderous, fat fish. He actually looks happy now. I did some research as a result of this incident, and have decided to write a strongly worded letter to the pet store manager. Fatty is an angelfish which are very aggressive towards fish like Anex, who was a neon fish, so NO, they did NOT get along just fine. So moral of the story, please research your aquatic friends before you buy them, failure to do so may result in cannibalism, which is frowned upon in most societies.