I was disappointed with the show because i liked the characters and i wanted to see more of them.

So would I, but what I think didn't get acknowledged enough in the discussion about CoE is that no one knew at the time whether there even would be a fourth season, and from what I gather it didn't seem very likely until after the success of CoE. I can't link you the source, but I read an interview with RTD where he said that the ending of CoE was written in a way that would tie the story up neatly, in case that really was the end of TW.