Probably just a lousy customer service rep. I've had Comcast internet service at our house for almost eight years now. I think I've had to call three times about outages. Each time they have been very professional and showed up the next day to fix the problem. One time I called on a Saturday and they showed up on Sunday morning. Might also depend on where you are. Better luck in the future!
They are supposed to act professionally at all times. Since you called in you should receive an email with a survey to fill out, make sure you fill it out and grade it how you feel you were treated. I get one every time I call in, when you chat there is one at the end of the chat to fill out.