Does anyone know what this movie is called about a company?

I watched this movie quite a while ago and don't remember the names of any actors. I do know however that the movie is about a group of ambitious men who start to work in a company. They have to call people and try to sell insurances I believe, but somehow get crazy rich. Obviously they are scamming the people and the movie comes to its climax where one of the main characters is directly scamming one of the people he got to know. I also remember them trying to sell things over the phone. Mentioning this guidebook on how to convince callers who are in doubt and how to recognize callers who will end up saying no anyways. Can anyone help me or does anyone know what movie this is!?!